Prey items were identified from the stomachs of wintering Mountain Plovers (Charadrius montanus) collected in California at the Pixley National Wildlife Refuge and Carrizo Plain Natural Area in 1991, and south of the Salton Sea in 1992. Stomach contents of the 39 birds included 2,092 different food items representing 13 orders and at least 16 families of invertebrates. Diets at each of the three locales differed greatly, with coleopterans and hymenopterans dominating the Carrizo samples, lepidopterans the Pixley samples, and coleopterans and orthopterans the Salton Sea samples. Diets of males and females were similar. These findings counter the current perception that Mountain Plover diets are specialized on coleopterans and orthopterans, and bring the species more in line as a dietary generalist/opportunist as reported for most shorebirds.