KGS

SEC source: 0001193125-26-100823 · ownership.xml · nonDerivative · entry 2

McKee Robert Michael · CIK 0001971122 · Director · President & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 399,835.477

F2 · security: Represents an award of performance based restricted stock units the payout of which was subject to the achievement of performance metrics related to discretionary cash flow, consolidated net leverage ratio, absolute total shareholder return and an ESG scorecard over the period of June 28, 2023 to December 31, 2025. The Personnel and Compensation Committee certified the shares with a vest date of March 8, 2026. The restricted stock units converted into shares of common stock on a one-for-one basis.

SEC source: 0001193125-26-100823 · ownership.xml · nonDerivative · entry 1

McKee Robert Michael · CIK 0001971122 · Director · President & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 219,835.477

F1 · security: The reported securities are restricted stock units that vest and settle in shares of common stock in three equal installments beginning March 8, 2027.

SEC source: 0001193125-26-100788 · ownership.xml · nonDerivative · entry 3

Roclawski Cory Anne · CIK 0001971066 · EVP & CHRO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 63,418

F3 · security: Issuer withheld shares to satisfy the tax withholding obligations associated with the vesting of restricted shares.

SEC source: 0001193125-26-100788 · ownership.xml · nonDerivative · entry 2

Roclawski Cory Anne · CIK 0001971066 · EVP & CHRO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 77,149

F2 · security: The reported securities are restricted stock units that vest and settle in shares of common stock in three equal installments beginning March 8, 2027.

SEC source: 0001193125-26-100788 · ownership.xml · nonDerivative · entry 1

Roclawski Cory Anne · CIK 0001971066 · EVP & CHRO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 69,992

F1 · security: Represents an award of performance based restricted stock units the payout of which was subject to the achievement of performance metrics related to discretionary cash flow, consolidated net leverage ratio, absolute total shareholder return and an ESG scorecard over the period of June 28, 2023 to December 31, 2025. The Personnel and Compensation Committee certified the shares with a vest date of March 8, 2026. The restricted stock units converted into shares of common stock on a one-for-one basis.

SEC source: 0001193125-26-100682 · ownership.xml · nonDerivative · entry 1

Howard Jennifer LeGrand · CIK 0002100638 · See Remarks

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 20,763

F1 · security: The reported securities are restricted stock units that vest and settle in shares of common stock in three equal installments beginning March 8, 2027.

SEC source: 0001193125-26-067567 · ownership.xml · nonDerivative · entry 1

McKee Robert Michael · CIK 0001971122 · Director · President & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 187,628.477

F1 · security: Shares of Common Stock acquired through automatic dividend reinvestment of cash dividends in the Reporting Person's brokerage account.

F2 · balance_after: Includes 695 shares of Common Stock acquired since the Reporting Person's last Form 4 through participation in the Issuer's Employee Stock Purchase Plan.

SEC source: 0001193125-26-006796 · ownership.xml · nonDerivative · entry 1

Buhigas Pedro R. · CIK 0001814898 · Chief Information Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 87,219

F1 · security: Issuer withheld shares to satisfy the tax withholding obligations associated with the vesting of restricted shares.

SEC source: 0001193125-26-006702 · ownership.xml · nonDerivative · entry 1

Hamilton Ewan William · CIK 0001971110 · EVP & Chief Accounting Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 33,855

F1 · security: Issuer withheld shares to satisfy the tax withholding obligations associated with the vesting of restricted shares.

SEC source: 0001193125-26-006678 · ownership.xml · nonDerivative · entry 1

Griggs John · CIK 0001714049 · Executive VP & CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 67,378

F1 · security: Issuer withheld shares to satisfy the tax withholding obligations associated with the vesting of restricted shares.

SEC source: 0001193125-26-006694 · ownership.xml · nonDerivative · entry 1

Lenamon William Chad · CIK 0001971854 · Executive Vice President & COO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 55,657

F1 · security: Issuer withheld shares to satisfy the tax withholding obligations associated with the vesting of restricted shares.

SEC source: 0001193125-26-006690 · ownership.xml · nonDerivative · entry 1

Roclawski Cory Anne · CIK 0001971066 · EVP & CHRO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 42,992

F1 · security: Issuer withheld shares to satisfy the tax withholding obligations associated with the vesting of restricted shares.

F2 · balance_after: Includes 194 shares of Common Stock acquired since the Reporting Person's last Form 4 through participation in the Issuer's Employee Stock Purchase Plan.

SEC source: 0000950130-25-000300 · ownership.xml · nonDerivative · entry 1

Howard Jennifer LeGrand · CIK 0002100638 · EVP, Gen. Counsel & Corp Sec

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 13,606

F1 · security: The reported securities are restricted stock units that vest and settle in shares of common stock in three equal installments beginning December 8, 2026.

SEC source: 0001193125-25-306904 · ownership.xml · nonDerivative · entry 1

Frontier TopCo Partnership, L.P. · CIK 0001767028 · 10% owner

EQT Fund Management S.a r.l. · CIK 0001834239 · 10% owner

Frontier Topco GP, LLC · CIK 0001972628 · 10% owner

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

10b5-1 filing: No plan indicated

Ownership: Indirect · Held by Frontier TopCo Partnership, L.P.

Disclosed balance after: 0

F1 · price: Consists of shares of common stock, par value $0.01 per share, of the Issuer ("Common Stock") that were sold in an underwritten secondary offering (the "Offering") at a price to the public of $34.60 per share. The Reporting Person received $34.37 per share of Common Stock sold in the Offering, which is the public offering price less certain underwriting discounts.

F2 · ownership.nature: Consists of shares of common stock held directly by Frontier TopCo Partnership, L.P. ("Kodiak Holdings"). Frontier TopCo GP, LLC ("Frontier GP") is the general partner of Kodiak Holdings. EQT Infrastructure III SCSp ("EQT Infrastructure III") indirectly owns 100% of the membership interests in Frontier GP. EQT Fund Management S.a r.l. ("EFMS") has exclusive responsibility for the management and control of the business and affairs of investment vehicles which constitute the majority of the total commitments to EQT Infrastructure III. As such, EFMS has the power to control Frontier GP's voting and investment decisions and may be deemed to have beneficial ownership of any securities held by Kodiak Holdings.

SEC source: 0001193125-25-282891 · ownership.xml · nonDerivative · entry 1

Frontier TopCo Partnership, L.P. · CIK 0001767028 · 10% owner

EQT Fund Management S.a r.l. · CIK 0001834239 · 10% owner

Frontier Topco GP, LLC · CIK 0001972628 · 10% owner

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

10b5-1 filing: No plan indicated

Ownership: Indirect · Held by Frontier TopCo Partnership, L.P.

Disclosed balance after: 9,762,573

F1 · price: Consists of shares of common stock, par value $0.01 per share, of the Issuer ("Common Stock") that were sold in an underwritten secondary offering (the "Offering") at a price to the public of $33.60 per share. The Reporting Person received $33.321 per share of Common Stock sold in the Offering, which is the public offering price less certain underwriting discounts.

F2 · ownership.nature: Consists of shares of common stock held directly by Frontier TopCo Partnership, L.P. ("Kodiak Holdings"). Frontier TopCo GP, LLC ("Frontier GP") is the general partner of Kodiak Holdings. EQT Infrastructure III SCSp ("EQT Infrastructure III") indirectly owns 100% of the membership interests in Frontier GP. EQT Fund Management S.a r.l. ("EFMS") has exclusive responsibility for the management and control of the business and affairs of investment vehicles which constitute the majority of the total commitments to EQT Infrastructure III. As such, EFMS has the power to control Frontier GP's voting and investment decisions and may be deemed to have beneficial ownership of the securities held by Kodiak Holdings.

SEC source: 0002080986-25-000004 · ownership.xml · nonDerivative · entry 1

Green Steven Lee · CIK 0002080986 · EVP & Chief Commercial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 14,157

F1 · security: The reported securities are restricted stock units that vest and settle in shares of common stock in three equal installments beginning September 8, 2026.

SEC source: 0000950170-25-113973 · ownership.xml · nonDerivative · entry 1

Frontier TopCo Partnership, L.P. · CIK 0001767028 · 10% owner

EQT Fund Management S.a r.l. · CIK 0001834239 · 10% owner

Frontier Topco GP, LLC · CIK 0001972628 · 10% owner

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

10b5-1 filing: No plan indicated

Ownership: Indirect · Held by Frontier TopCo Partnership, L.P.

Disclosed balance after: 19,762,573

F1 · price: Consists of shares of common stock, par value $0.01 per share, of the Issuer ("Common Stock") that were sold in an underwritten secondary offering (the "Offering") at a price to the public of $34.40 per share. The Reporting Person received $34.211 per share of Common Stock sold in the Offering, which is the public offering price less certain underwriting discounts.

F2 · ownership.nature: Consists of shares of common stock held directly by Frontier TopCo Partnership, L.P. ("Kodiak Holdings"). Frontier TopCo GP, LLC ("Frontier GP") is the general partner of Kodiak Holdings. EQT Infrastructure III SCSp ("EQT Infrastructure III") indirectly owns 100% of the membership interests in Frontier GP. EQT Fund Management S.a r.l. ("EFMS") has exclusive responsibility for the management and control of the business and affairs of investment vehicles which constitute the majority of the total commitments to EQT Infrastructure III. As such, EFMS has the power to control Frontier GP's voting and investment decisions and may be deemed to have beneficial ownership of the securities held by Kodiak Holdings.

SEC source: 0001767295-25-000007 · ownership.xml · nonDerivative · entry 1

Bullock William L. Jr. · CIK 0001767295 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 2,676

F1 · security: The reported securities are restricted stock units that will vest and settle in shares of common stock on the earlier of April 23, 2026 and the next annual meeting of stockholders following the date of grant.

SEC source: 0000950170-25-108020 · ownership.xml · nonDerivative · entry 1

Frontier TopCo Partnership, L.P. · CIK 0001767028 · 10% owner

EQT Fund Management S.a r.l. · CIK 0001834239 · 10% owner

Frontier Topco GP, LLC · CIK 0001972628 · 10% owner

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

10b5-1 filing: No plan indicated

Ownership: Indirect · Held by Frontier TopCo Partnership, L.P.

Disclosed balance after: 29,762,573

F1 · price: Consists of shares of common stock, par value $0.01 per share, of the Issuer ("Common Stock") held by the Reporting Person that were repurchased by the Issuer at the closing price per share on August 11, 2025.

F2 · ownership.nature: Consists of shares of Common Stock held directly by Frontier TopCo Partnership, L.P. ("Kodiak Holdings"). Frontier TopCo GP, LLC ("Frontier GP") is the general partner of Kodiak Holdings. EQT Infrastructure III SCSp ("EQT Infrastructure III") indirectly owns 100% of the membership interests in Frontier GP. EQT Fund Management S.a r.l. ("EFMS") has exclusive responsibility for the management and control of the business and affairs of investment vehicles which constitute the majority of the total commitments to EQT Infrastructure III. As such, EFMS has the power to control Frontier GP's voting and investment decisions and may be deemed to have beneficial ownership of the securities held by Kodiak Holdings.

SEC source: 0000950170-25-094339 · ownership.xml · nonDerivative · entry 1

Lenamon William Chad · CIK 0001971854 · Executive Vice President & COO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 56,304

F1 · security: Issuer withheld shares to satisfy the tax withholding obligations associated with the vesting of restricted shares.

SEC source: 0000950170-25-094334 · ownership.xml · nonDerivative · entry 1

McKee Robert Michael · CIK 0001971122 · Director · President & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 186,500

F1 · security: Issuer withheld shares to satisfy the tax withholding obligations associated with the vesting of restricted shares.

SEC source: 0000950170-25-094332 · ownership.xml · nonDerivative · entry 1

Hamilton Ewan William · CIK 0001971110 · EVP & Chief Accounting Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 34,829

F1 · security: Issuer withheld shares to satisfy the tax withholding obligations associated with the vesting of restricted shares.

SEC source: 0000950170-25-094340 · ownership.xml · nonDerivative · entry 1

Griggs John · CIK 0001714049 · Executive VP & CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 68,595

F1 · security: Issuer withheld shares to satisfy the tax withholding obligations associated with the vesting of restricted shares.

SEC source: 0000950170-25-094392 · ownership.xml · nonDerivative · entry 1

Lenamon William Chad · CIK 0001971854 · Executive Vice President & COO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 56,304

F1 · security: This is an amendment to the original Form 4 filed on July 7, 2025 to correct an administrative error of the reported date of transaction of July 7, 2025 to July 3, 2025 and to include indirect beneficial ownership.

F2 · shares: Issuer withheld shares to satisfy the tax withholding obligations associated with the vesting of restricted shares.

SEC source: 0000950170-25-094391 · ownership.xml · nonDerivative · entry 1

McKee Robert Michael · CIK 0001971122 · Director · President & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 186,500

F1 · security: This is an amendment to the original Form 4 filed on July 7, 2025 to correct an administrative error of the reported date of transaction of July 7, 2025 to July 3, 2025 and to include indirect beneficial ownership.

F2 · shares: Issuer withheld shares to satisfy the tax withholding obligations associated with the vesting of restricted shares.

SEC source: 0000950170-25-094337 · ownership.xml · nonDerivative · entry 1

Roclawski Cory Anne · CIK 0001971066 · EVP & CHRO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 43,772

F1 · security: Issuer withheld shares to satisfy the tax withholding obligations associated with the vesting of restricted shares.

SEC source: 0000950170-25-094335 · ownership.xml · nonDerivative · entry 1

Battle Kelly Michelle · CIK 0001971076 · Executive Vice President, CLO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 48,159

F1 · security: Issuer withheld shares to satisfy the tax withholding obligations associated with the vesting of restricted shares.

SEC source: 0000950170-25-071360 · ownership.xml · nonDerivative · entry 2

Frontier TopCo Partnership, L.P. · CIK 0001767028 · 10% owner

EQT Fund Management S.a r.l. · CIK 0001834239 · 10% owner

Frontier Topco GP, LLC · CIK 0001972628 · 10% owner

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

10b5-1 filing: No plan indicated

Ownership: Indirect · Held by Frontier TopCo Partnership, L.P.

Disclosed balance after: 31,271,323

F2 · shares: Consists of shares of Common Stock held by Kodiak Holdings that, concurrently with the Rule 144 Sale, were repurchased by the Issuer at the Rule 144 Sale Price.

F3 · ownership.nature: Consists of shares of common stock held directly by Frontier TopCo Partnership, L.P. ("Kodiak Holdings"). Frontier TopCo GP, LLC ("Frontier GP") is the general partner of Kodiak Holdings. EQT Infrastructure III SCSp ("EQT Infrastructure III") indirectly owns 100% of the membership interests in Frontier GP. EQT Fund Management S.a r.l. ("EFMS") has exclusive responsibility for the management and control of the business and affairs of investment vehicles which constitute the majority of the total commitments to EQT Infrastructure III. As such, EFMS has the power to control Frontier GP's voting and investment decisions and may be deemed to have beneficial ownership of the securities held by Kodiak Holdings.

SEC source: 0000950170-25-071360 · ownership.xml · nonDerivative · entry 1

Frontier TopCo Partnership, L.P. · CIK 0001767028 · 10% owner

EQT Fund Management S.a r.l. · CIK 0001834239 · 10% owner

Frontier Topco GP, LLC · CIK 0001972628 · 10% owner

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

10b5-1 filing: No plan indicated

Ownership: Indirect · Held by Frontier TopCo Partnership, L.P.

Disclosed balance after: 31,548,985

F1 · shares: On May 12, 2025, Kodiak Holdings (as defined below) enlisted J.P. Morgan Securities LLC as broker in connection with the sale of 3,222,338 shares of common stock, par value $0.01 per share, of the Issuer ("Common Stock") pursuant to Rule 144 under the Securities Act of 1933, as amended (the "Rule 144 Sale"). Kodiak Holdings received $36.015 per share of Common Stock sold in the Rule 144 Sale, which is the public offering price less certain broker discounts (the "Rule 144 Sale Price").

F3 · ownership.nature: Consists of shares of common stock held directly by Frontier TopCo Partnership, L.P. ("Kodiak Holdings"). Frontier TopCo GP, LLC ("Frontier GP") is the general partner of Kodiak Holdings. EQT Infrastructure III SCSp ("EQT Infrastructure III") indirectly owns 100% of the membership interests in Frontier GP. EQT Fund Management S.a r.l. ("EFMS") has exclusive responsibility for the management and control of the business and affairs of investment vehicles which constitute the majority of the total commitments to EQT Infrastructure III. As such, EFMS has the power to control Frontier GP's voting and investment decisions and may be deemed to have beneficial ownership of the securities held by Kodiak Holdings.

SEC source: 0000950170-25-058139 · ownership.xml · nonDerivative · entry 1

Holloway Gretchen Lynn · CIK 0001971780 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 19,406

F1 · security: The reported securities are restricted stock units that will vest and settle in shares of common stock on the earlier of April 23, 2026 and the next annual meeting of stockholders following the date of grant.

SEC source: 0000950170-25-058153 · ownership.xml · nonDerivative · entry 1

Drumgoole Christopher · CIK 0001879205 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 20,406

F1 · security: The reported securities are restricted stock units that will vest and settle in shares of common stock on the earlier of April 23, 2026 and the next annual meeting of stockholders following the date of grant.

SEC source: 0000950170-25-058182 · ownership.xml · nonDerivative · entry 1

HOGAN RANDALL J · CIK 0001189049 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,406

F1 · security: The reported securities are restricted stock units that will vest and settle in shares of common stock on the earlier of April 23, 2026 and the next annual meeting of stockholders following the date of grant.

SEC source: 0000950170-25-058224 · ownership.xml · nonDerivative · entry 1

Duplantier Jon-Al · CIK 0001472434 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 20,406

F1 · security: The reported securities are restricted stock units that will vest and settle in shares of common stock on the earlier of April 23, 2026 and the next annual meeting of stockholders following the date of grant.

SEC source: 0000950170-25-058180 · ownership.xml · nonDerivative · entry 1

Bonno Terry · CIK 0001608699 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 32,406

F1 · security: The reported securities are restricted stock units that will vest and settle in shares of common stock on the earlier of April 23, 2026 and the next annual meeting of stockholders following the date of grant.

SEC source: 0000950170-25-058146 · ownership.xml · nonDerivative · entry 1

Montana Margaret C · CIK 0001623188 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 26,516

F1 · security: The reported securities are restricted stock units that will vest and settle in shares of common stock on the earlier of April 23, 2026 and the next annual meeting of stockholders following the date of grant.

SEC source: 0000950170-25-037352 · ownership.xml · nonDerivative · entry 2

Hamilton Ewan William · CIK 0001971110 · EVP & Chief Accounting Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 37,043

F2 · security: Issuer withheld shares to satisfy the tax withholding obligations associated with the vesting of restricted shares.

SEC source: 0000950170-25-037352 · ownership.xml · nonDerivative · entry 1

Hamilton Ewan William · CIK 0001971110 · EVP & Chief Accounting Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 38,401

F1 · security: The reported securities are restricted stock units that vest and settle in shares of common stock in three equal installments beginning March 8, 2026.

SEC source: 0000950170-25-037353 · ownership.xml · nonDerivative · entry 2

Griggs John · CIK 0001714049 · Executive VP & CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 72,367

F2 · security: Issuer withheld shares to satisfy the tax withholding obligations associated with the vesting of restricted shares.

SEC source: 0000950170-25-037353 · ownership.xml · nonDerivative · entry 1

Griggs John · CIK 0001714049 · Executive VP & CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 74,978

F1 · security: The reported securities are restricted stock units that vest and settle in shares of common stock in three equal installments beginning March 8, 2026.

SEC source: 0000950170-25-037355 · ownership.xml · nonDerivative · entry 3

Lenamon William Chad · CIK 0001971854 · Executive Vice President & COO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 58,053

F2 · security: Issuer withheld shares to satisfy the tax withholding obligations associated with the vesting of restricted shares.

SEC source: 0000950170-25-037355 · ownership.xml · nonDerivative · entry 1

Lenamon William Chad · CIK 0001971854 · Executive Vice President & COO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 59,346

F1 · security: The reported securities are restricted stock units that vest and settle in shares of common stock in three equal installments beginning March 8, 2026.

SEC source: 0000950170-25-037351 · ownership.xml · nonDerivative · entry 2

Roclawski Cory Anne · CIK 0001971066 · EVP & CHRO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 46,478

F2 · security: Issuer withheld shares to satisfy the tax withholding obligations associated with the vesting of restricted shares.

SEC source: 0000950170-25-037351 · ownership.xml · nonDerivative · entry 1

Roclawski Cory Anne · CIK 0001971066 · EVP & CHRO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 48,045

F1 · security: The reported securities are restricted stock units that vest and settle in shares of common stock in three equal installments beginning March 8, 2026.

SEC source: 0000950170-25-037346 · ownership.xml · nonDerivative · entry 2

Battle Kelly Michelle · CIK 0001971076 · Executive Vice President, CLO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 50,619

F2 · security: Issuer withheld shares to satisfy the tax withholding obligations associated with the vesting of restricted shares.

SEC source: 0000950170-25-037346 · ownership.xml · nonDerivative · entry 1

Battle Kelly Michelle · CIK 0001971076 · Executive Vice President, CLO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 52,707

F1 · security: The reported securities are restricted stock units that vest and settle in shares of common stock in three equal installments beginning March 8, 2026.

SEC source: 0000950170-25-037349 · ownership.xml · nonDerivative · entry 3

McKee Robert Michael · CIK 0001971122 · Director · President & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 196,338

F3 · security: Issuer withheld shares to satisfy the tax withholding obligations associated with the vesting of restricted shares.

SEC source: 0000950170-25-037349 · ownership.xml · nonDerivative · entry 1

McKee Robert Michael · CIK 0001971122 · Director · President & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 204,148

F1 · security: The reported securities are restricted stock units that vest and settle in shares of common stock in three equal installments beginning March 8, 2026.

SEC source: 0000950170-25-012341 · ownership.xml · nonDerivative · entry 1

Frontier TopCo Partnership, L.P. · CIK 0001767028 · 10% owner

EQT Fund Management S.a r.l. · CIK 0001834239 · 10% owner

Frontier Topco GP, LLC · CIK 0001972628 · 10% owner

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

10b5-1 filing: No plan indicated

Ownership: Indirect · Held by Frontier TopCo Partnership, L.P.

Disclosed balance after: 34,771,323

F1 · shares: On January 30, 2025, Kodiak Holdings (as defined below) enlisted Goldman Sachs & Co. LLC as market maker in connection with the sale of 3,728,677 shares of common stock, par value $0.01 per share, of the Issuer ("Common Stock") pursuant to Rule 144 under the Securities Act of 1933, as amended. The Reporting Person received $46.80 per share of Common Stock sold in the sale, which is the public offering price less certain broker discounts.

F2 · ownership.nature: Consists of shares of common stock held directly by Frontier TopCo Partnership, L.P. ("Kodiak Holdings"). Frontier TopCo GP, LLC ("Frontier GP") is the general partner of Kodiak Holdings. EQT Infrastructure III SCSp ("EQT Infrastructure III") indirectly owns 100% of the membership interests in Frontier GP. EQT Fund Management S.a r.l. ("EFMS") has exclusive responsibility for the management and control of the business and affairs of investment vehicles which constitute the majority of the total commitments to EQT Infrastructure III. As such, EFMS has the power to control Frontier GP's voting and investment decisions and may be deemed to have beneficial ownership of the securities held by Kodiak Holdings.

SEC source: 0000950170-25-003565 · ownership.xml · nonDerivative · entry 1

Hamilton Ewan William · CIK 0001971110 · EVP and CAO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 30,771

F1 · security: Issuer withheld shares to satisfy the tax withholding obligations associated with the vesting of restricted shares.

SEC source: 0000950170-25-003569 · ownership.xml · nonDerivative · entry 1

Griggs John · CIK 0001714049 · Executive VP & CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 57,372

F1 · security: Issuer withheld shares to satisfy the tax withholding obligations associated with the vesting of restricted shares.