TUSK

SEC source: 0001450919-18-000003 · wf-form4_154214350923801.xml · nonDerivative · entry 1

Straehla Arty · CIK 0001450919 · Director · Chief Executive Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 199,007

F1 · shares: These shares were sold to satisfy tax withholding obligations incurred in connection with the vesting of restricted stock units previously granted under the issuer's equity incentive plan.

F2 · price: The price reported in Column 4 is a weighted average sale price. These shares were sold in multiple transactions at prices ranging from $26.26 per share to $27.25 per share, inclusive. The reporting person undertakes to provide to Mammoth Energy Services, Inc. any security holder of Mammoth Energy Services, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes 2, 3 and 4 of this Form 4.

SEC source: 0000899243-18-021021 · doc4.xml · nonDerivative · entry 1

GULFPORT ENERGY CORP · CIK 0000874499 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 9,829,548

F1 · shares: These shares of common stock, par value $0.01 per share ("Common Stock") of Mammoth Energy Services, Inc. (the "Issuer"), were sold by Gulfport Energy Corporation ("Gulfport") to the underwriters in a secondary public offering of Common Stock at a price of $38.01 per share in connection with the underwriters' partial exercise of their option to purchase additional shares of the Issuer's Common Stock from Gulfport and the other selling stockholder granted by such selling stockholders in the previously reported June 2018 secondary offering (the "Option Exercise"). The Option Exercise closed on July 30, 2018.

F2 · balance_after: Of these securities, 4,877 are unvested restricted stock units ("RSUs") that were granted under the Issuer's 2016 Equity Incentive Plan and were assigned to Gulfport by its director designee to the Issuer's board of directors under the terms of his employment with Gulfport. Such director designee previously reported the acquisition of the RSUs in his Form 4 filings and indicated that these were assigned to Gulfport. Of these 4,877 unvested RSUs, 2,222 will vest on October 19, 2018 and 2,655 will vest on the earlier of June 7, 2019 and the date of the Issuer's 2019 Annual Meeting of Stockholders. Each RSU represents a contingent right to receive one share of Common Stock of the Issuer.

SEC source: 0001048462-18-000035 · form4.xml · nonDerivative · entry 2

MEH SUB LLC · CIK 0001710079 · Director · 10% owner

WEXFORD CAPITAL LP · CIK 0001048462 · Director · 10% owner

Wexford GP LLC · CIK 0001472112 · Director · 10% owner

DAVIDSON CHARLES E · CIK 0001001391 · Director · 10% owner

JACOBS JOSEPH · CIK 0001048485 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 21,978,893

F3 · shares: These shares of common stock of the Issuer were sold by MEH SUB LLC ("MEH") to the underwriters in a secondary public offering of the common stock at a price of $38.01 per share, in connection with the underwriters' partial exercise of their option to purchase additional shares of the Issuer's common stock from MEH and the other selling stockholder granted by such selling stockholders in the previously reported June 2018 secondary offering (the "Option Exercise"). The Option Exercise closed on July 30, 2018. Other material terms of the Offering are described in the Form 424B5, dated June 19, 2018, filed by the Issuer with the SEC on June 28, 2018.

F3 · price: These shares of common stock of the Issuer were sold by MEH SUB LLC ("MEH") to the underwriters in a secondary public offering of the common stock at a price of $38.01 per share, in connection with the underwriters' partial exercise of their option to purchase additional shares of the Issuer's common stock from MEH and the other selling stockholder granted by such selling stockholders in the previously reported June 2018 secondary offering (the "Option Exercise"). The Option Exercise closed on July 30, 2018. Other material terms of the Offering are described in the Form 424B5, dated June 19, 2018, filed by the Issuer with the SEC on June 28, 2018.

F4 · ownership.direct: Wexford Capital may, by reason of its status as manager of MEH, be deemed to own beneficially the securities of which MEH possesses beneficial ownership. Wexford GP LLC ("Wexford GP") may, as the General Partner of Wexford Capital, be deemed to own beneficially the securities of which MEH possesses beneficial ownership. Each of Charles E. Davidson ("Davidson") and Joseph M. Jacobs ("Jacobs") may, by reason of his status as a controlling person of Wexford GP, be deemed to own beneficially the securities of which MEH possesses beneficial ownership. Each of Wexford Capital, Wexford GP, Davidson and Jacobs share the power to vote and to dispose of the securities beneficially owned by MEH. Each of Wexford Capital, Wexford GP, Davidson and Jacobs disclaim beneficial ownership of the securities owned by MEH and this report shall not be deemed as an admission that they are the beneficial owners of such securities, except to the extent of any pecuniary interests therein.

SEC source: 0000899243-18-019188 · doc4.xml · nonDerivative · entry 1

GULFPORT ENERGY CORP · CIK 0000874499 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 9,948,522

F1 · shares: These shares of common stock, par value $0.01 per share ("Common Stock") of Mammoth Energy Services, Inc. (the "Issuer"), were sold by Gulfport Energy Corporation ("Gulfport") to the underwriters in a secondary public offering of Common Stock (the "Offering") at a price of $38.01 per share, which offering closed on June 29, 2018.

F2 · balance_after: Of these securities, 4,877 are unvested restricted stock units ("RSUs") that were granted under the Issuer's 2016 Equity Incentive Plan and were assigned to Gulfport by its director designee to the Issuer's board of directors under the terms of his employment with Gulfport. Such director designee previously reported the acquisition of the RSUs in his Form 4 filings and indicated that these were assigned to Gulfport. Of these 4,877 unvested RSUs, 2,222 will vest on October 19, 2018 and 2,655 will vest on the earlier of June 7, 2019 and the date of the Issuer's 2019 Annual Meeting of Stockholders. Each RSU represents a contingent right to receive one share of Common Stock of the Issuer.

SEC source: 0001048462-18-000030 · form4.xml · nonDerivative · entry 2

MEH SUB LLC · CIK 0001710079 · Director · 10% owner

WEXFORD CAPITAL LP · CIK 0001048462 · Director · 10% owner

Wexford GP LLC · CIK 0001472112 · Director · 10% owner

DAVIDSON CHARLES E · CIK 0001001391 · Director · 10% owner

JACOBS JOSEPH · CIK 0001048485 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 22,244,919

F3 · shares: These shares of common stock of the Issuer were sold by MEH SUB LLC ("MEH") to the underwriters in a secondary public offering of the common stock (the "Offering") at a price of $38.01 per share, which Offering closed on June 29, 2018. Other material terms of the Offering are described in the Form 424B5, dated June 19, 2018, filed by the Issuer with the SEC on June 28, 2018.

F3 · price: These shares of common stock of the Issuer were sold by MEH SUB LLC ("MEH") to the underwriters in a secondary public offering of the common stock (the "Offering") at a price of $38.01 per share, which Offering closed on June 29, 2018. Other material terms of the Offering are described in the Form 424B5, dated June 19, 2018, filed by the Issuer with the SEC on June 28, 2018.

F4 · ownership.direct: Wexford Capital may, by reason of its status as manager of MEH, be deemed to own beneficially the securities of which MEH possesses beneficial ownership. Wexford GP LLC ("Wexford GP") may, as the General Partner of Wexford Capital, be deemed to own beneficially the securities of which MEH possesses beneficial ownership. Each of Charles E. Davidson ("Davidson") and Joseph M. Jacobs ("Jacobs") may, by reason of his status as a controlling person of Wexford GP, be deemed to own beneficially the securities of which MEH possesses beneficial ownership. Each of Wexford Capital, Wexford GP, Davidson and Jacobs share the power to vote and to dispose of the securities beneficially owned by MEH. Each of Wexford Capital, Wexford GP, Davidson and Jacobs disclaim beneficial ownership of the securities owned by MEH and this report shall not be deemed as an admission that they are the beneficial owners of such securities, except to the extent of any pecuniary interests therein.

SEC source: 0000899243-18-016071 · doc4.xml · nonDerivative · entry 1

SMITH ARTHUR L · CIK 0001034323 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 12,235

F1 · shares: These securities are restricted stock units that were granted under the issuer's equity incentive plan, representing an annual non-employee director grant. These securities will vest on the earlier of June 7, 2019 and the date of the issuer's 2019 Annual Meeting of Stockholders. Each restricted stock unit represents a contingent right to receive one share of common stock, par value $0.01 per share, of the issuer.

SEC source: 0000899243-18-016074 · doc4.xml · nonDerivative · entry 1

Heerwagen Paul K IV · CIK 0001694037 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 2,655

F1 · shares: These securities are restricted stock units that were granted under the issuer's equity incentive plan, representing an annual non-employee director grant. These securities will vest on the earlier of June 7, 2019 and the date of the issuer's 2019 Annual Meeting of Stockholders. Each restricted stock unit represents a contingent right to receive one share of common stock, par value $0.01 per share, of the issuer. These restricted stock units have been assigned to Gulfport Energy Corporation under the terms of Mr. Heerwagen's employment with Gulfport Energy Corporation. As a result, Mr. Heerwagen disclaims any pecuniary interest in these restricted stock units.

F1 · balance_after: These securities are restricted stock units that were granted under the issuer's equity incentive plan, representing an annual non-employee director grant. These securities will vest on the earlier of June 7, 2019 and the date of the issuer's 2019 Annual Meeting of Stockholders. Each restricted stock unit represents a contingent right to receive one share of common stock, par value $0.01 per share, of the issuer. These restricted stock units have been assigned to Gulfport Energy Corporation under the terms of Mr. Heerwagen's employment with Gulfport Energy Corporation. As a result, Mr. Heerwagen disclaims any pecuniary interest in these restricted stock units.

F1 · ownership.direct: These securities are restricted stock units that were granted under the issuer's equity incentive plan, representing an annual non-employee director grant. These securities will vest on the earlier of June 7, 2019 and the date of the issuer's 2019 Annual Meeting of Stockholders. Each restricted stock unit represents a contingent right to receive one share of common stock, par value $0.01 per share, of the issuer. These restricted stock units have been assigned to Gulfport Energy Corporation under the terms of Mr. Heerwagen's employment with Gulfport Energy Corporation. As a result, Mr. Heerwagen disclaims any pecuniary interest in these restricted stock units.

SEC source: 0000899243-18-016072 · doc4.xml · nonDerivative · entry 1

Ross Matthew · CIK 0001689613 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 12,235

F1 · shares: These securities are restricted stock units that were granted under the issuer's equity incentive plan, representing an annual non-employee director grant. These securities will vest on the earlier of June 7, 2019 and the date of the issuer's 2019 Annual Meeting of Stockholders. Each restricted stock unit represents a contingent right to receive one share of common stock, par value $0.01 per share, of the issuer.

SEC source: 0001048462-18-000028 · form4.xml · nonDerivative · entry 1

McCarthy Marc T · CIK 0001471993 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 2,655

F1 · security: These securities are restricted stock units that were granted under the issuer's equity incentive plan, representing an annual non-employee director grant. These securities will vest on the earlier of June 7, 2019 or the date of the issuer's 2019 Annual Meeting of Stockholders. Each restricted stock unit represents a contingent right to receive one share of common stock, par value $0.01 per share, of the issuer. These restricted stock units have been assigned to Wexford Capital LP under the terms of Mr. McCarthy's employment with Wexford Capital LP. As a result, Mr. McCarthy disclaims any interest in these restricted stock units, except for his pecuniary interest therein.

F1 · shares: These securities are restricted stock units that were granted under the issuer's equity incentive plan, representing an annual non-employee director grant. These securities will vest on the earlier of June 7, 2019 or the date of the issuer's 2019 Annual Meeting of Stockholders. Each restricted stock unit represents a contingent right to receive one share of common stock, par value $0.01 per share, of the issuer. These restricted stock units have been assigned to Wexford Capital LP under the terms of Mr. McCarthy's employment with Wexford Capital LP. As a result, Mr. McCarthy disclaims any interest in these restricted stock units, except for his pecuniary interest therein.

F1 · balance_after: These securities are restricted stock units that were granted under the issuer's equity incentive plan, representing an annual non-employee director grant. These securities will vest on the earlier of June 7, 2019 or the date of the issuer's 2019 Annual Meeting of Stockholders. Each restricted stock unit represents a contingent right to receive one share of common stock, par value $0.01 per share, of the issuer. These restricted stock units have been assigned to Wexford Capital LP under the terms of Mr. McCarthy's employment with Wexford Capital LP. As a result, Mr. McCarthy disclaims any interest in these restricted stock units, except for his pecuniary interest therein.

SEC source: 0000899243-18-016073 · doc4.xml · nonDerivative · entry 1

Palm James D · CIK 0001346557 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 19,725

F1 · shares: These securities are restricted stock units that were granted under the issuer's equity incentive plan, representing an annual non-employee director grant. These securities will vest on the earlier of June 7, 2019 and the date of the issuer's 2019 Annual Meeting of Stockholders. Each restricted stock unit represents a contingent right to receive one share of common stock, par value $0.01 per share, of the issuer.

SEC source: 0000899243-18-006754 · doc4.xml · nonDerivative · entry 1

Layton Mark E. · CIK 0001687210 · CFO and Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 52,702

F1 · shares: These shares were sold to satisfy tax withholding obligations incurred in connection with the vesting of restricted stock units previously granted under the issuer's equity incentive plan.

SEC source: 0000899243-18-002987 · doc4.xml · nonDerivative · entry 1

SMITH ARTHUR L · CIK 0001034323 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 9,580

F1 · shares: These securities are restricted stock units that were granted under the issuer's equity incentive plan, representing a portion of the annual director grant, pro-rated for the service period beginning on October 20, 2017 and ending on June 8, 2018 and vesting on the earlier of June 8, 2018 and the date of the issuer's 2018 Annual Meeting of Stockholders. Each restricted stock unit represents a contingent right to receive one share of common stock, par value $0.01 per share, of the issuer.

SEC source: 0000899243-18-002992 · doc4.xml · nonDerivative · entry 1

Heerwagen Paul K IV · CIK 0001694037 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 2,913

F1 · shares: These securities are restricted stock units that were granted under the issuer's equity incentive plan, representing a portion of the annual director grant, pro-rated for the service period beginning on October 20, 2017 and ending on June 8, 2018 and vesting on the earlier of June 8, 2018 and the date of the issuer's 2018 Annual Meeting of Stockholders. Each restricted stock unit represents a contingent right to receive one share of common stock, par value $0.01 per share, of the issuer. These restricted stock units have been assigned to Gulfport Energy Corporation under the terms of Mr. Heerwagen's employment with Gulfport Energy Corporation. As a result, Mr. Heerwagen disclaims any pecuniary interest in these restricted stock units.

F1 · balance_after: These securities are restricted stock units that were granted under the issuer's equity incentive plan, representing a portion of the annual director grant, pro-rated for the service period beginning on October 20, 2017 and ending on June 8, 2018 and vesting on the earlier of June 8, 2018 and the date of the issuer's 2018 Annual Meeting of Stockholders. Each restricted stock unit represents a contingent right to receive one share of common stock, par value $0.01 per share, of the issuer. These restricted stock units have been assigned to Gulfport Energy Corporation under the terms of Mr. Heerwagen's employment with Gulfport Energy Corporation. As a result, Mr. Heerwagen disclaims any pecuniary interest in these restricted stock units.

F1 · ownership.direct: These securities are restricted stock units that were granted under the issuer's equity incentive plan, representing a portion of the annual director grant, pro-rated for the service period beginning on October 20, 2017 and ending on June 8, 2018 and vesting on the earlier of June 8, 2018 and the date of the issuer's 2018 Annual Meeting of Stockholders. Each restricted stock unit represents a contingent right to receive one share of common stock, par value $0.01 per share, of the issuer. These restricted stock units have been assigned to Gulfport Energy Corporation under the terms of Mr. Heerwagen's employment with Gulfport Energy Corporation. As a result, Mr. Heerwagen disclaims any pecuniary interest in these restricted stock units.

SEC source: 0000899243-18-002989 · doc4.xml · nonDerivative · entry 1

Ross Matthew · CIK 0001689613 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 9,580

F1 · shares: These securities are restricted stock units that were granted under the issuer's equity incentive plan, representing a portion of the annual director grant, pro-rated for the service period beginning on October 20, 2017 and ending on June 8, 2018 and vesting on the earlier of June 8, 2018 and the date of the issuer's 2018 Annual Meeting of Stockholders. Each restricted stock unit represents a contingent right to receive one share of common stock, par value $0.01 per share, of the issuer.

SEC source: 0001140361-18-005391 · doc1.xml · nonDerivative · entry 1

McCarthy Marc T · CIK 0001471993 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 2,913

F1 · security: These securities are restricted stock units that were granted under the issuer's equity incentive plan, representing a portion of the annual director grant, pro-rated for the service period beginning on October 20, 2017 and ending on June 8, 2018 and vesting on the earlier of June 8, 2018 and the date of the issuer's 2018 Annual Meeting of Stockholders. Each restricted stock unit represents a contingent right to receive one share of common stock, par value $0.01 per share, of the issuer. These restricted stock units have been assigned to Wexford Capital LP under the terms of Mr. McCarthy's employment with Wexford Capital LP. As a result, Mr. McCarthy disclaims any interest in these restricted stock units, except for his pecuniary interest therein.

F1 · shares: These securities are restricted stock units that were granted under the issuer's equity incentive plan, representing a portion of the annual director grant, pro-rated for the service period beginning on October 20, 2017 and ending on June 8, 2018 and vesting on the earlier of June 8, 2018 and the date of the issuer's 2018 Annual Meeting of Stockholders. Each restricted stock unit represents a contingent right to receive one share of common stock, par value $0.01 per share, of the issuer. These restricted stock units have been assigned to Wexford Capital LP under the terms of Mr. McCarthy's employment with Wexford Capital LP. As a result, Mr. McCarthy disclaims any interest in these restricted stock units, except for his pecuniary interest therein.

F1 · balance_after: These securities are restricted stock units that were granted under the issuer's equity incentive plan, representing a portion of the annual director grant, pro-rated for the service period beginning on October 20, 2017 and ending on June 8, 2018 and vesting on the earlier of June 8, 2018 and the date of the issuer's 2018 Annual Meeting of Stockholders. Each restricted stock unit represents a contingent right to receive one share of common stock, par value $0.01 per share, of the issuer. These restricted stock units have been assigned to Wexford Capital LP under the terms of Mr. McCarthy's employment with Wexford Capital LP. As a result, Mr. McCarthy disclaims any interest in these restricted stock units, except for his pecuniary interest therein.

F1 · ownership.direct: These securities are restricted stock units that were granted under the issuer's equity incentive plan, representing a portion of the annual director grant, pro-rated for the service period beginning on October 20, 2017 and ending on June 8, 2018 and vesting on the earlier of June 8, 2018 and the date of the issuer's 2018 Annual Meeting of Stockholders. Each restricted stock unit represents a contingent right to receive one share of common stock, par value $0.01 per share, of the issuer. These restricted stock units have been assigned to Wexford Capital LP under the terms of Mr. McCarthy's employment with Wexford Capital LP. As a result, Mr. McCarthy disclaims any interest in these restricted stock units, except for his pecuniary interest therein.

SEC source: 0000899243-18-002986 · doc4.xml · nonDerivative · entry 1

Palm James D · CIK 0001346557 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 17,070

F1 · shares: These securities are restricted stock units that were granted under the issuer's equity incentive plan, representing a portion of the annual director grant, pro-rated for the service period beginning on June 26, 2017 and ending on June 8, 2018 and vesting on the earlier of June 8, 2018 and the date of the issuer's 2018 Annual Meeting of Stockholders. Each restricted stock unit represents a contingent right to receive one share of common stock, par value $0.01 per share, of the issuer.

SEC source: 0000899243-17-026659 · doc4.xml · nonDerivative · entry 2

Straehla Arty · CIK 0001450919 · Director · Chief Executive Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 224,158

F1 · shares: These shares were sold to satisfy tax withholding obligations incurred in connection with the vesting of restricted stock units previously granted under the issuer's equity incentive plan.

F3 · price: The price reported in Column 4 is a weighted average sale price. These shares were sold in multiple transactions at prices ranging from $17.52 per share to $18.11 per share, inclusive.

SEC source: 0000899243-17-026660 · doc4.xml · nonDerivative · entry 1

Layton Mark E. · CIK 0001687210 · CFO and Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 57,075

F1 · shares: These shares were sold to satisfy tax withholding obligations incurred in connection with the vesting of restricted stock units previously granted under the issuer's equity incentive plan.

F2 · price: The price reported in Column 4 is a weighted average sale price. These shares were sold in multiple transactions at prices ranging from $18.75 per share to $19.13 per share, inclusive. The reporting person undertakes to provide to Mammoth Energy Services, Inc., any security holder of Mammoth Energy Services, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

SEC source: 0000899243-17-026659 · doc4.xml · nonDerivative · entry 1

Straehla Arty · CIK 0001450919 · Director · Chief Executive Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 231,711

F1 · shares: These shares were sold to satisfy tax withholding obligations incurred in connection with the vesting of restricted stock units previously granted under the issuer's equity incentive plan.

F2 · price: The price reported in Column 4 is a weighted average sale price. These shares were sold in multiple transactions at prices ranging from $18.50 per share to $19.11 per share, inclusive. The reporting person undertakes to provide to Mammoth Energy Services, Inc., any security holder of Mammoth Energy Services, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes 2 and 3 of this Form 4.

SEC source: 0000899243-17-021102 · doc4.xml · nonDerivative · entry 2

Palm James D · CIK 0001346557 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 12,700

F1 · shares: These securities are held jointly with the reporting person's spouse.

F3 · price: The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $12.45 to $12.75 per share, inclusive.

F1 · balance_after: These securities are held jointly with the reporting person's spouse.

SEC source: 0000899243-17-021102 · doc4.xml · nonDerivative · entry 1

Palm James D · CIK 0001346557 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 10,700

F1 · shares: These securities are held jointly with the reporting person's spouse.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $12.72 to $12.92 per share, inclusive. The reporting person undertakes to provide to Mammoth Energy Services, Inc., any security holder of Mammoth Energy Services, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the ranges set forth in footnotes 1 and 2.

F1 · balance_after: These securities are held jointly with the reporting person's spouse.

SEC source: 0000899243-17-016254 · doc4.xml · nonDerivative · entry 1

SMITH ARTHUR L · CIK 0001034323 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · By Arthur L. Smith Family LP

Disclosed balance after: 6,000

F1 · ownership.direct: These shares of common stock are held by Arthur L. Smith Family LP, which is managed by Arthur L. Smith Management LLC, of which Mr. Smith is the manager.

F1 · ownership.nature: These shares of common stock are held by Arthur L. Smith Family LP, which is managed by Arthur L. Smith Management LLC, of which Mr. Smith is the manager.

SEC source: 0001140361-17-025875 · doc1.xml · nonDerivative · entry 2

MEH SUB LLC · CIK 0001710079 · Director · 10% owner

WEXFORD CAPITAL LP · CIK 0001048462 · Director · 10% owner

Wexford GP LLC · CIK 0001472112 · 10% owner

DAVIDSON CHARLES E · CIK 0001001391 · Director · 10% owner

JACOBS JOSEPH · CIK 0001048485 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 25,009,319

F2 · shares: The shares of common stock reported herein were issued to MEH Sub LLC ("MEH SUB") in exchange for MEH SUB's contribution of its membership interest in each of (1) Sturgeon Acquisitions LLC, a Delaware limited liability company; (2) Stingray Energy Services LLC, a Delaware limited liability company; and (3) Stingray Cementing LLC, a Delaware limited liability company. The issuance of the shares of common stock reported herein was approved by the board of directors of the Issuer in advance.

F2 · price: The shares of common stock reported herein were issued to MEH Sub LLC ("MEH SUB") in exchange for MEH SUB's contribution of its membership interest in each of (1) Sturgeon Acquisitions LLC, a Delaware limited liability company; (2) Stingray Energy Services LLC, a Delaware limited liability company; and (3) Stingray Cementing LLC, a Delaware limited liability company. The issuance of the shares of common stock reported herein was approved by the board of directors of the Issuer in advance.

F3 · ownership.direct: The shares of common stock reported herein are held by MEH SUB. The shares of common stock previously reported as being held by Mammoth Energy Holding LLC were transferred to MEH SUB in an internal reorganization. This form is jointly filed by MEH SUB, Wexford, Wexford GP LLC ("Wexford GP"), Charles E. Davidson ("Davidson") and Joseph M. Jacobs ("Jacobs"). Wexford serves as manager to MEH SUB and as such may be deemed to share beneficial ownership of the common stock held by MEH, but disclaims such beneficial ownership to the extent such beneficial ownership exceeds its pecuniary interest. (*continued under Footnote (4) below).

F4 · ownership.direct: (*continued from Footnote (3) above) Wexford GP, as the general partner of Wexford, may be deemed to share beneficial ownership of the common stock held by MEH SUB, but disclaims such beneficial ownership to the extent such beneficial ownership exceeds its pecuniary interest. Messrs. Davidson and Jacobs, as the controlling persons of Wexford GP, may be deemed to share beneficial ownership of any common stock held by MEH SUB for which Wexford serves as manager, but disclaim such beneficial ownership to the extent such beneficial ownership exceeds their respective pecuniary interest therein.

SEC source: 0000899243-18-004028 · doc5.xml · nonDerivative · entry 1

GULFPORT ENERGY CORP · CIK 0000874499 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 11,181,467

F1 · price: On June 5, 2017, Gulfport Energy Corporation ("Gulfport") received 2,098,137 shares of common stock, par value $0.01 per share ("Common Stock"), of Mammoth Energy Services, Inc. (the "Issuer") from the Issuer as consideration for Gulfport's contribution of its membership interests in Sturgeon Acquisitions LLC, Stingray Energy Services LLC and Stingray Cementing LLC pursuant to three contribution agreements, each dated as of March 20, 2017, and as amended and restated on May 12, 2017, by and among Gulfport, the Issuer and certain other contributors party thereto, and each of which was approved in advance by the board of directors of the Issuer.

F1 · balance_after: On June 5, 2017, Gulfport Energy Corporation ("Gulfport") received 2,098,137 shares of common stock, par value $0.01 per share ("Common Stock"), of Mammoth Energy Services, Inc. (the "Issuer") from the Issuer as consideration for Gulfport's contribution of its membership interests in Sturgeon Acquisitions LLC, Stingray Energy Services LLC and Stingray Cementing LLC pursuant to three contribution agreements, each dated as of March 20, 2017, and as amended and restated on May 12, 2017, by and among Gulfport, the Issuer and certain other contributors party thereto, and each of which was approved in advance by the board of directors of the Issuer.

F2 · balance_after: Of these securities, 5,135 are unvested restricted stock units ("RSUs") that were granted under the Issuer's 2016 Equity Incentive Plan and were assigned to Gulfport by its director designees to the Issuer's board of directors under the terms of their respective employment with Gulfport. Such director designees previously reported the acquisition of the RSUs in their respective Form 4 filings and indicated that these were assigned to Gulfport. Of these 5,135 unvested RSUs, 2,222 will vest on October 19, 2018 and 2,913 will vest on the earlier of June 8, 2018 and the date of the Issuer's 2018 Annual Meeting of Stockholders. Each RSU represents a contingent right to receive one share of Common Stock of the Issuer.

SEC source: 0000899243-17-006146 · doc4.xml · nonDerivative · entry 1

Straehla Arty · CIK 0001450919 · Director · Chief Executive Officer

10b5-1 filing: Not disclosed

Ownership: Indirect · As custodian for grandchild's UTMA account.

Disclosed balance after: 460

F1 · balance_after: The shares are held in a custodial account for the benefit of Mr. Straehla's grandchild. Mr. Straehla maintains investment control over the account and may be deemed to have beneficial ownership of these shares.

F1 · ownership.direct: The shares are held in a custodial account for the benefit of Mr. Straehla's grandchild. Mr. Straehla maintains investment control over the account and may be deemed to have beneficial ownership of these shares.

F1 · ownership.nature: The shares are held in a custodial account for the benefit of Mr. Straehla's grandchild. Mr. Straehla maintains investment control over the account and may be deemed to have beneficial ownership of these shares.

SEC source: 0000899243-17-005110 · doc4.xml · nonDerivative · entry 1

Layton Mark E. · CIK 0001687210 · CFO and Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 58,000

F1 · shares: These securities are restricted stock units that were granted under the issuer's 2016 Equity Incentive Plan. Each restricted stock unit represents a contingent right to receive one share of common stock of the issuer. All of these units will vest in three substantially equal annual installments beginning on February 21, 2018.

SEC source: 0000899243-16-033093 · doc4.xml · nonDerivative · entry 1

Ross Matthew · CIK 0001689613 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 6,667

F1 · shares: These securities are restricted stock units that were granted under the issuer's 2016 Equity Incentive Plan. 2,223 of these restricted stock units vested on November 7, 2016, and the remaining 4,444 restricted stock units will vest in two equal annual installments beginning on October 19, 2017. Each restricted stock unit represents a contingent right to receive one share of common stock, par value $0.01 per share, of the issuer.

SEC source: 0000899243-16-032195 · doc4.xml · nonDerivative · entry 2

GULFPORT ENERGY CORP · CIK 0000874499 · Director · 10% owner

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 9,080,417

F2 · shares: These shares of comon stock were sold by Gulfport to the underwriters in the IPO at a price of $14.0625 per share.

F3 · balance_after: Of these securities, 9,073,750 shares of common stock were received by Gulfport in connection with Gulfport's contribution of its membership interests in Mammoth Energy Partners LLC to the Issuer, which was completed prior to the IPO and approved by the board of directors of the Issuer in advance.

SEC source: 0001140361-16-083276 · doc1.xml · nonDerivative · entry 2

Mammoth Energy Holdings LLC · CIK 0001623083 · Director · 10% owner

WEXFORD CAPITAL LP · CIK 0001048462 · Director · 10% owner

Wexford GP LLC · CIK 0001472112 · Director · 10% owner

DAVIDSON CHARLES E · CIK 0001001391 · Director · 10% owner

JACOBS JOSEPH · CIK 0001048485 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 20,445,923

F2 · shares: These shares were sold to the underwriters in the IPO at a price of $14.0625 per share.

F3 · balance_after: The shares of common stock were received by MEH in connection with MEH's contribution of its membership interest in Mammoth Energy Partners LLC to the Issuer completed prior to the IPO, which contribution was approved by the board of directors of the Issuer in advance.

F4 · ownership.direct: This form is jointly filed by MEH, the owner of the common stock reported on this line, Wexford, Wexford GP LLC ("Wexford GP"), Charles E. Davidson ("Davidson") and Joseph M. Jacobs ("Jacobs"). The common stock shown as beneficially owned by Davidson, Jacobs, Wexford GP and Wexford, reflect the common stock that were owned of record by MEH. Wexford serves as manager for MEH and as such may be deemed to share beneficial ownership of the common stock beneficially owned by MEH, but disclaims such beneficial ownership to the extent such beneficial ownership exceeds its pecuniary interest. (*continued under Footnote (5) below).

F5 · ownership.direct: (*continued from Footnote (4) above) Wexford GP, as the general partner of Wexford, may be deemed to share beneficial ownership of the common stock beneficially owned by MEH, but disclaims such beneficial ownership to the extent such beneficial ownership exceeds its pecuniary interest. Messrs. Davidson and Jacobs, as the controlling persons of Wexford GP, may be deemed to share beneficial ownership of any common stock beneficially owned by MEH for which Wexford serves as manager, but disclaim such beneficial ownership to the extent such beneficial ownership exceeds their pecuniary interest.

SEC source: 0000899243-16-032187 · doc4.xml · nonDerivative · entry 1

SMITH ARTHUR L · CIK 0001034323 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 6,667

F1 · shares: These securities are restricted stock units that were granted under the issuer's 2016 Equity Incentive Plan. 2,223 of these restricted stock units vested on October 19, 2016, and the remaining 4,444 restricted stock units will vest in two equal annual installments beginning on October 19, 2017. Each restricted stock unit represents a contingent right to receive one share of common stock, par value $0.01 per share, of the issuer.

SEC source: 0000899243-16-032184 · doc4.xml · nonDerivative · entry 1

Weiss Andre · CIK 0001687235 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 6,667

F1 · shares: These securities are restricted stock units that were granted under the issuer's 2016 Equity Incentive Plan. 2,223 of these restricted stock units vested on October 19, 2016, and the remaining 4,444 restricted stock units will vest in two equal annual installments beginning on October 19, 2017. Each restricted stock unit represents a contingent right to receive one share of common stock, par value $0.01 per share, of the issuer.

SEC source: 0000899243-16-032189 · doc4.xml · nonDerivative · entry 2

Layton Mark E. · CIK 0001687210 · CFO and Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 18,000

F2 · shares: These securities are restricted stock units that were granted under the Issuer's 2016 Equity Incentive Plan. All of these units will vest in four equal annual installments beginning on October 19, 2017. Each restricted stock unit represents a contingent right to receive one share of Common Stock of the Issuer.

SEC source: 0000899243-16-032189 · doc4.xml · nonDerivative · entry 1

Layton Mark E. · CIK 0001687210 · CFO and Secretary

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 3,000

F1 · shares: These shares of common stock, par value $0.01 per share (the "Common Stock"), of Mammoth Energy Services, Inc. (the "Issuer") were purchased under the directed share program in connection with the Issuer's initial public offering (the "IPO"). The underwriters reserved for sale at the IPO price up to 5% of the Common Stock being offered in the IPO for sale to the Issuer's employees, executive officers, directors, business associates and related persons at the public offering price. Shares of Common Stock bought by the reporting person in the directed share program are subject to a lock-up agreement entered into by the reporting person in connection with the IPO.

SEC source: 0001140361-16-083281 · doc1.xml · nonDerivative · entry 1

McCarthy Marc T · CIK 0001471993 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 6,667

F1 · security: These securities are restricted stock units that were granted under the 2016 Equity Incentive Plan of Mammoth Energy Services, Inc. (the "Issuer"). 2,223 of these restricted stock units vested on October 19, 2016, and the remaining 4,444 restricted stock units will vest in two equal annual installments beginning on October 19, 2017. Each restricted stock unit represents a contingent right to receive one share of common stock of the Issuer, par value $0.01 per share. These restricted stock units have been assigned to Wexford Capital LP under the terms of Mr. McCarthy's employment with Wexford Capital LP. As a result, Mr. McCarthy disclaims any pecuniary interest in these restricted stock units.

F1 · shares: These securities are restricted stock units that were granted under the 2016 Equity Incentive Plan of Mammoth Energy Services, Inc. (the "Issuer"). 2,223 of these restricted stock units vested on October 19, 2016, and the remaining 4,444 restricted stock units will vest in two equal annual installments beginning on October 19, 2017. Each restricted stock unit represents a contingent right to receive one share of common stock of the Issuer, par value $0.01 per share. These restricted stock units have been assigned to Wexford Capital LP under the terms of Mr. McCarthy's employment with Wexford Capital LP. As a result, Mr. McCarthy disclaims any pecuniary interest in these restricted stock units.

F1 · balance_after: These securities are restricted stock units that were granted under the 2016 Equity Incentive Plan of Mammoth Energy Services, Inc. (the "Issuer"). 2,223 of these restricted stock units vested on October 19, 2016, and the remaining 4,444 restricted stock units will vest in two equal annual installments beginning on October 19, 2017. Each restricted stock unit represents a contingent right to receive one share of common stock of the Issuer, par value $0.01 per share. These restricted stock units have been assigned to Wexford Capital LP under the terms of Mr. McCarthy's employment with Wexford Capital LP. As a result, Mr. McCarthy disclaims any pecuniary interest in these restricted stock units.

F1 · ownership.direct: These securities are restricted stock units that were granted under the 2016 Equity Incentive Plan of Mammoth Energy Services, Inc. (the "Issuer"). 2,223 of these restricted stock units vested on October 19, 2016, and the remaining 4,444 restricted stock units will vest in two equal annual installments beginning on October 19, 2017. Each restricted stock unit represents a contingent right to receive one share of common stock of the Issuer, par value $0.01 per share. These restricted stock units have been assigned to Wexford Capital LP under the terms of Mr. McCarthy's employment with Wexford Capital LP. As a result, Mr. McCarthy disclaims any pecuniary interest in these restricted stock units.

SEC source: 0000899243-16-032186 · doc4.xml · nonDerivative · entry 3

Straehla Arty · CIK 0001450919 · Director · Chief Executive Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 251,332

F3 · shares: These securities are restricted stock units that were granted under the Issuer's 2016 Equity Incentive Plan. All of these units will vest in three substantially equal installments beginning on October 19, 2017. Each restricted stock unit represents a contingent right to receive one share of common stock of the Issuer.

SEC source: 0000899243-16-032186 · doc4.xml · nonDerivative · entry 2

Straehla Arty · CIK 0001450919 · Director · Chief Executive Officer

10b5-1 filing: Not disclosed

Ownership: Indirect · As custodian for grandchild's UTMA account

Disclosed balance after: 1,332

F1 · shares: These shares of common stock, par value $0.01 per share (the "Common Stock"), of Mammoth Energy Services, Inc. (the "Issuer") were purchased under the directed share program in connection with the Issuer's initial public offering (the "IPO"). The underwriters reserved for sale at the IPO price up to 5% of the Common Stock being offered in the IPO for sale to the Issuer's employees, executive officers, directors, business associates and related persons at the public offering price. Shares of Common Stock bought by the reporting person in the directed share program are subject to a lock-up agreement entered into by the reporting person in connection with the IPO.

F2 · ownership.direct: The shares are held in a custodial account for the benefit of two of Mr. Straehla's grandchildren. Mr. Straehla maintains investment control over the account.

F2 · ownership.nature: The shares are held in a custodial account for the benefit of two of Mr. Straehla's grandchildren. Mr. Straehla maintains investment control over the account.

SEC source: 0000899243-16-032186 · doc4.xml · nonDerivative · entry 1

Straehla Arty · CIK 0001450919 · Director · Chief Executive Officer

10b5-1 filing: Not disclosed

Ownership: Indirect · As custodian for grandchild's UTMA account

Disclosed balance after: 666

F1 · shares: These shares of common stock, par value $0.01 per share (the "Common Stock"), of Mammoth Energy Services, Inc. (the "Issuer") were purchased under the directed share program in connection with the Issuer's initial public offering (the "IPO"). The underwriters reserved for sale at the IPO price up to 5% of the Common Stock being offered in the IPO for sale to the Issuer's employees, executive officers, directors, business associates and related persons at the public offering price. Shares of Common Stock bought by the reporting person in the directed share program are subject to a lock-up agreement entered into by the reporting person in connection with the IPO.

F2 · ownership.direct: The shares are held in a custodial account for the benefit of two of Mr. Straehla's grandchildren. Mr. Straehla maintains investment control over the account.

F2 · ownership.nature: The shares are held in a custodial account for the benefit of two of Mr. Straehla's grandchildren. Mr. Straehla maintains investment control over the account.

SEC source: 0000899243-16-032197 · doc4.xml · nonDerivative · entry 1

Gaydosik Aaron · CIK 0001617605 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 6,667

F1 · shares: These securities are restricted stock units that were granted under the issuer's 2016 Equity Incentive Plan. 2,223 of these restricted stock units vested on October 19, 2016, and the remaining 4,444 restricted stock units will vest in two equal annual installments beginning on October 19, 2017. Each restricted stock unit represents a contingent right to receive one share of common stock, par value $0.01 per share, of the issuer. These restricted stock units have been assigned to Gulfport Energy Corporation under the terms of Mr. Gaydosik's employment with Gulfport Energy Corporation. As a result, Mr. Gaydosik disclaims any pecuniary interest in these restricted stock units.

F1 · balance_after: These securities are restricted stock units that were granted under the issuer's 2016 Equity Incentive Plan. 2,223 of these restricted stock units vested on October 19, 2016, and the remaining 4,444 restricted stock units will vest in two equal annual installments beginning on October 19, 2017. Each restricted stock unit represents a contingent right to receive one share of common stock, par value $0.01 per share, of the issuer. These restricted stock units have been assigned to Gulfport Energy Corporation under the terms of Mr. Gaydosik's employment with Gulfport Energy Corporation. As a result, Mr. Gaydosik disclaims any pecuniary interest in these restricted stock units.

F1 · ownership.direct: These securities are restricted stock units that were granted under the issuer's 2016 Equity Incentive Plan. 2,223 of these restricted stock units vested on October 19, 2016, and the remaining 4,444 restricted stock units will vest in two equal annual installments beginning on October 19, 2017. Each restricted stock unit represents a contingent right to receive one share of common stock, par value $0.01 per share, of the issuer. These restricted stock units have been assigned to Gulfport Energy Corporation under the terms of Mr. Gaydosik's employment with Gulfport Energy Corporation. As a result, Mr. Gaydosik disclaims any pecuniary interest in these restricted stock units.

SEC source: 0000899243-17-001043 · doc4.xml · nonDerivative · entry 1

Heerwagen Paul K IV · CIK 0001694037 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 4,444

F1 · shares: These securities are restricted stock units that were granted under the issuer's 2016 Equity Incentive Plan. These restricted stock units will vest in two equal annual installments beginning on October 19, 2017. Each restricted stock unit represents a contingent right to receive one share of common stock, par value $0.01 per share, of the issuer. These restricted stock units have been assigned to Gulfport Energy Corporation under the terms of Mr. Heerwagen's employment with Gulfport Energy Corporation. As a result, Mr. Heerwagen disclaims any pecuniary interest in these restricted stock units.

F1 · balance_after: These securities are restricted stock units that were granted under the issuer's 2016 Equity Incentive Plan. These restricted stock units will vest in two equal annual installments beginning on October 19, 2017. Each restricted stock unit represents a contingent right to receive one share of common stock, par value $0.01 per share, of the issuer. These restricted stock units have been assigned to Gulfport Energy Corporation under the terms of Mr. Heerwagen's employment with Gulfport Energy Corporation. As a result, Mr. Heerwagen disclaims any pecuniary interest in these restricted stock units.

F1 · ownership.direct: These securities are restricted stock units that were granted under the issuer's 2016 Equity Incentive Plan. These restricted stock units will vest in two equal annual installments beginning on October 19, 2017. Each restricted stock unit represents a contingent right to receive one share of common stock, par value $0.01 per share, of the issuer. These restricted stock units have been assigned to Gulfport Energy Corporation under the terms of Mr. Heerwagen's employment with Gulfport Energy Corporation. As a result, Mr. Heerwagen disclaims any pecuniary interest in these restricted stock units.