The overall goal of our project is the continuing development of a framework for estimating high-resolution carbon stocks and dynamics and future carbon sequestration potential using remote sensing and ecosystem modeling linked with existing field observation systems such as the USFS Forest Inventory. In particular, we seek to demonstrate an approach that provides the basis for the rapid expansion from Maryland to nearby states, and which additionally enables the monitoring of annualized changes in stocks through time at fine spatial resolution. We believe this build-out is possible today and is a critical step in the development of a national CMS. Specifically we will address the following objectives: (1) Improve our existing methodology for carbon stock estimation and uncertainty based on lessons learned from our Phase 2 study; (2) Provide wall-to-wall, high-resolution estimates of carbon stocks and their uncertainties for the 3-state region of Pennsylvania, Delaware and Maryland; (3) Initialize and run a prognostic ecosystem model for carbon at high-spatial resolution over multiple eastern states; (4) Validate national biomass maps using Forest Inventory and Analysis (FIA) data and high-resolution biomass maps over an expanded domain; (5) Develop and test methods for monitoring changes in carbon stocks through time using repeat lidar data, satellite imagery, forest inventory data, and remote sensing driven mechanistic modeling; (6) Demonstrate MRV efficacy to meet stakeholder needs in our 3-state region, and a vision for future national-scale deployment. Our work has followed a logical expansion of effort, from proof-of concept starting with just two counties in our Phase 1 pilot study, to an entire state (24 counties) in Phase 2. This research has emphatically demonstrated the feasibility of large-scale mapping using airborne lidar. We propose to build on these efforts to encompass another qualitative increase in spatial extent, new MRV-relevant product prototyping, and a vision for future operational deployment of MRV systems that are responsive to local, national and international interests in management and policy.