Northwest Natural Holding Company Watch

from 10-Q 25 pages ===================================================================== Northwest Natural Gas Company to Deutsche Bank Trust Company Americas (Formerly Known as Bankers Trust Company),

from 10-K 85 pages Northwest Natural Holding Company $100,000,000 5.78% Senior Notes, Series A, Due March 7, 2028 $50,000,000 5.84% Senior Notes, Series B, Due March 7, 2029 Note Purchase Agreement Dated December 14, 2023

from 8-K 37 pages ===================================================================== Northwest Natural Gas Company to Deutsche Bank Trust Company Americas (Formerly Known as Bankers Trust Company), as Corporate Trustee Under the Mortgage and Deed of Trust, Dated as of July 1, 1946, of Portland Gas & Coke Company (Now Northwest Natural Gas Company) Twenty-Sixth Supplemental Indenture Providing, Among Other Things, for First Mortgage Bonds, 5.18% Series Due 2034 and First Mortgage Bonds, 5.23% Series Due 2038 Dated as of July 1, 2023 ===================================================================== Twenty-Sixth Supplemental Indenture

from 8-K 25 pages ===================================================================== Northwest Natural Gas Company to Deutsche Bank Trust Company Americas (Formerly Known as Bankers Trust Company), as Corporate Trustee Under the Mortgage and Deed of Trust, Dated as of July 1, 1946, of Portland Gas & Coke Company (Now Northwest Natural Gas Company) Twenty-Fifth Supplemental Indenture Providing, Among Other Things, for First Mortgage Bonds, 5.43% Series Due 2053 Dated as of December 1, 2022 ===================================================================== Twenty-Fifth Supplemental Indenture

from 8-K 25 pages ===================================================================== Northwest Natural Gas Company to Deutsche Bank Trust Company Americas (Formerly Known as Bankers Trust Company), as Corporate Trustee Under the Mortgage and Deed of Trust, Dated as of July 1, 1946, of Portland Gas & Coke Company (Now Northwest Natural Gas Company) Twenty-Fourth Supplemental Indenture Providing, Among Other Things, for First Mortgage Bonds, 4.78% Series Due 2052 Dated as of September 1, 2022 ===================================================================== Twenty-Fourth Supplemental Indenture

from 10-K 4 pages Description of Northwest Natural Holding Company’s Securities Registered Pursuant to Section 12 of the Securities Exchange Act of 1934

from S-3ASR 9 pages Northwest Natural Holding Company Officer’s Certificate Creating the Debentures, Series Due

from S-3ASR 79 pages Northwest Natural Holding Company to , Trustee Indenture (For Unsecured Debt Securities) Dated as of , Northwest Natural Holding Company Reconciliation and Tie Between Trust Indenture Act of 1939 and Indenture (For Unsecured Debt Securities) Dated as of ,

from S-3ASR 9 pages Northwest Natural Holding Company Officer’s Certificate Creating the Subordinated Debentures Due

from S-3ASR 86 pages Northwest Natural Holding Company to , Trustee Indenture (For Unsecured Subordinated Debt Securities) Dated as of , Northwest Natural Holding Company