Georectified mosaics of historical aerial photographs of the Colorado River in Parker Valley, Arizona and California, acquired in 1930, 1938, and 1947

The products provided here include four georectified mosaics of historic aerial photographs for the Parker Valley region within western Arizona and southeastern California. There are three individual mosaics from 1930, 1938, and 1947 covering different geographic areas. The fourth georectified mosaic is a composite of the three and covers the entire area of interest. These datasets were developed to portray the geologic characteristics of the lower Colorado River floodplain in the Parker Valley region and will serve as primary resources to help create a geologic map depicting the floodplain and river channel features prior to significant flow regulation by Hoover Dam and subsequently, Parker Dam. The composite dataset was crafted to expand the coverage of floodplain areas with minimal overlap with areas of significant river channel changes in the 1930s. Georeferencing of individual photographs and mosaic generation were performed by Digital Aerial Solutions, LLC.

Also included are individual digital aerial photographs (original scans and georeferenced images) comprising 1930, 1938, and 1947 that cover the area of interest. Supplemental files include image footprints, georeferencing procedures and accuracy reports supplied by the contractor, and seamlines for each mosaic. All spatial data is in the NAD 1983 UTM Zone 11N coordinate system.