Bank Swallow Monitoring - River Miles [ds21]

This data set uses a shapefile from the California Department of Water Resources which was digitized from the "Sacramento River, Sloughs, and Tributaries, California, 1991 Aerial Atlas, Collinsville to Shasta Dam" published by the US Army Corps of Engineers, Sacramento District. This atlas was used by biologists while they were surveying for bank swallows from 1992 to 2000. The May 1984 edition of this atlas was used for locating river mile points during surveys from 1986 to 1991. River mile points in both atlases vary from those shown on USGS 24k quad maps and are provided here to facilitate the locating of the bank swallow nesting colonies which are described by river mile.