ABSTRACT: As part of an 11-state inventory, we censused the Double-crested Cormorant (Phalacrocorax auritus) in the interior of California from 2009 to 2012, using a combination of aerial, ground, and boat surveys. An estimated 8791 pairs breeding in the interior of the state in 2009–2012 exceeded the 7170 pairs estimated in 1998–1999. In both periods, cormorants were breeding in 9 of 11 ecoregions, but three-fourths were at one site—Mullet Island at the Salton Sea in the Sonoran Desert ecoregion (abandoned in 2014).