The Columbia Estuary Ecosystem Restoration Program (CEERP) was created after the year 2000 when the National Oceanic and Atmospheric Administration (NOAA) identified habitat restoration in the estuary as providing potential offsite mitigation for impacts of the Federal Columbia River Hydropower System on wild salmon and steelhead stocks.  Program development was led by Bonneville Power Administration and the U.S. Army Corps of Engineers with scientific support from Pacific Northwest National Laboratory (PNNL) and NOAA.  From the release of the Research, Monitoring, and Evaluation Plan in 2008, the necessity for Synthesis and Evaluation was identified.  This included the periodic synthesis and reporting of regional scale data and an approach to evaluate the cumulative beneficial effects of restoration. These syntheses would be applied to evaluate and refine the restoration and research elements of CEERP. Since the Plan, Synthesis Memoranda were released at 5-year intervals in 2013 and 2018, with cumulative effects publications in 2011 and 2016. A 25-year retrospective synthesis is in development.  While the first two memoranda were led by PNNL and NOAA, the current draft memorandum is driven by findings from a workshop that included 26 restoration experts who actively contribute to CEERP through their restoration and management roles. These included action agencies and regulators, federal and state agencies, research institutions, restoration practitioners, and non-profit organizations. These findings were synthesized with a new review of the published scientific literature on the Columbia River Estuary to ascertain the baseline knowledge in 2000 as compared to learning since through the CEERP investments in research, restoration, and monitoring of reference and restoration sites. Findings of the third synthesis memorandum are being applied to reenvision the research, monitoring, and evaluation framework and inform the design and engineering of restoration projects.