This is part of an ongoing monitoring project that the Biogeographic Data Branch of the California Department of Fish and Game (DFG), in collaboration with the Department of Water Resources and the DFG Water Branch, started in 1999 to track changes in the Suisun Marsh vegetation over time. This is the fourth update since the original map was made in 1999. The first update, conducted in 2000, is summarized in Vegetation Mapping of Suisun Marsh, Solano County: A Report to the California Department of Water Resources (Keeler-Wolf et al. 2000). The second update, done three years later in 2003, is summarized in Suisun Marsh Vegetation Mapping Change Detection 2003 (Vaghti and Keeler-Wolf 2004). The third update was done in 2006 (the report is not yet available to the public).