This study used data from field plots in urban areas to describe forest structure (e.g., tree numbers, density, basal area, species composition) for six land use categories in six California climate zones: Southern California Coast, Inland Empire, Inland Valley, Southwest Desert, Northern, and Interior West. Two types of field plot data were utilized. The first set of data include 702 randomly sampled 0.04 hectare (ha) plots obtained from i-Tree Eco plot data for Los Angeles (in 2007-2008), Santa Barbara (2012) and the Sacramento area (2007). The second set of data (687 plots, in 2011) consisted of 0.067 ha (four 0.017 ha subplots) plots based on the Forest Service Forest Inventory and Analysis (FIA) plot design. The number of plots collected varied by climate zone and a total of 3,796 trees were sampled. Data collection included percentage of tree canopy cover over the plot, tree species, stem diameter at breast height (1.37 meters above ground, dbh), tree height, crown width, distance and azimuth to buildings that fit the requirements as specified in the i-Tree Eco and Urban FIA manuals.