Great Mountain Partners LLC (the “Registrant” and, together with its affiliated entities as described below, “GMP”), a Delaware limited liability company, provides investment advisory services to investment funds privately offered to qualified investors in the United States and elsewhere. GMP’s clients include private investment funds (the “Funds,” and each, a “Fund”) to which GMP or its affiliates will provide discretionary investment advisory services. Such Funds may invest directly in operating entities (“Direct Funds”) or in third-party managed investment funds (“Investor Services Funds”). The Registrant or one of its affiliates serves as the general partner or manager of each of the Funds (each such entity in such capacity, a “General Partner”). Each General Partner is subject to the Investment Advisers Act of 1940, as amended (the “Advisers Act”) pursuant to the Registrant’s registration in accordance with SEC guidance. This Brochure also describes the business practices of the General Partners and, as applicable, any management companies or other special purpose entities functioning as “relying advisers” of the Registrant. The Direct Funds generally invest through negotiated transactions in operating entities, generally referred to herein as “portfolio companies.” GMP’s investment advisory services to the Direct Funds consist of identifying and evaluating investment opportunities, negotiating the terms of investments, managing and monitoring investments and achieving dispositions of such investments. Although investments are made predominantly in non-public companies, investments in public companies are permitted in certain circumstances. The senior principals or other personnel of GMP or its affiliates may serve on portfolio companies’ respective boards of directors or otherwise act to influence control over management of the portfolio companies in which the Direct Funds have invested. The Investor Services Funds generally invest in third-party managed funds (“Third-Party Funds”) and direct investments in companies and projects alongside such third-party funds (“Co- Investments”). GMP’s advisory services to the Funds are detailed in the applicable private placement memoranda or other offering documents (each, a “Memorandum”), investment management agreements, management services agreement, limited partnership, limited liability company or other operating agreements (each, a “Partnership Agreement” and, as applicable, together with any relevant Memorandum, the “Governing

Documents”) and are further described below under “Methods of Analysis, Investment Strategies and Risk of Loss.” Investors in the Funds participate in the overall investment program for the applicable Fund, but may be excused from a particular investment due to legal, regulatory or other agreed-upon circumstances pursuant to the relevant Governing Documents. The Funds or the General Partners may enter into side letters or other similar agreements (“Side Letters”) with certain investors that have the effect of establishing rights under, or altering or supplementing the terms (including economic or other terms) of, the relevant Governing Documents with respect to such investors. Additionally, from time to time and as permitted by the relevant Governing Documents, GMP expects to provide (or agree to provide) co-investment opportunities (including the opportunity to participate in co-investment vehicles) to certain investors or other persons, including other sponsors, market participants, finders, consultants and other service providers, GMP’s personnel and/or certain other persons associated with GMP (e.g., a vehicle formed by GMP’s principals to co- invest alongside a particular Fund’s transactions). Such co-investments typically involve investment and disposal of interests in the applicable portfolio company at the same time and on the same terms as the Fund making the investment. However, from time to time, for strategic and other reasons, a co-investor or co-investment vehicle may purchase a portion of an investment from one or more Funds after such Funds have consummated their investment in the portfolio company (also known as a post-closing sell-down or transfer). Any such purchase from a Fund by a co-investor or co-investment vehicle generally occurs shortly after the Fund’s completion of the investment to avoid any changes in valuation of the investment. Where appropriate, and in GMP’s sole discretion, GMP is authorized to charge interest on the purchase to the co-investor or co-investment vehicle (or otherwise equitably to adjust the purchase price under certain conditions), and to seek reimbursement to the relevant Fund for related costs. However, to the extent such amounts are not so charged or reimbursed, they generally will be borne by the relevant Fund. Jonathan Rotolo and Alexander Thomson each serve as managers and are members of the Registrant. GMP does not currently participate in any wrap fee programs. As of December 31, 2023, the Registrant has $10,592,680,510 in regulatory assets under management.