The Fishery Foundation of California with a grant from the US Fish and Wildlife Service (FWS), conducted a seine survey of the western Delta in the winter of 2005 and 2006. The survey was in conjunction with FFC monitoring at Kimball Island, a wetland mitigation bank developed by Wildlands Inc. on the southwest edge of west Sherman Island (Figure 1). The survey was also a supplement to the FWS Lower Sacramento River Seine Survey, which samples weekly at four boat-ramp seine sites in the western Delta. The purpose of the survey was to determine use of shallow water habitats in winter in the western Delta by young Chinook salmon. Our study focused on the timing, relative abundance, and habitat use patterns of young wild Chinook salmon. We did not attempt to address the importance of Delta rearing to the salmon populations.