The Grand Mayumba is a pilot project of the Gabonese Republic to develop a national plan, policy framework, and related technical tools under the United Nations Framework Convention on Climate Change (UNFCCC). The Grand Mayumba area includes commercial tropical forestry concessions, state-owned land, agriculture land, savanna, and national parks. Gabon’s sustainable development plan provides a diversified vision for conservation, sustainable forest management, plantation forestry development, and agricultural development. In support of Grand Mayumba, FLINTpro has been deployed to underpin the greenhouse gas accounting for the diverse activities being undertaken across the Grand Mayumba landscape. This involves the measurement of the project baseline, sustainable development scenario, and project accounting. Spatially explicit modeling capabilities of FLINTpro are enabling the integration of a suite of data inputs with activity-specific land management information. Focus lies on the design and implementation of FLINTpro as a reliable, repeatable, and efficient operating system to ensure that highly credible emissions accounting is achievable in a cost effective manner.