Rancho San Jose del Valle (also called "Rancho Agua Caliente" or "Warner's Rancho") was a 26,689-acre (108.01 km2) Mexican land grant in present-day San Diego County, California given in 1840 by Governor Juan B. Alvarado to Jose Antonio Pico, and then given in 1844 by Governor Manuel Micheltorena to Juan Jose Warner. The most northeasterly grant made within present-day San Diego County, it was bounded on the west by Palomar Mountain, and on the south by Buena Vista Creek and Rancho Valle de San Jose, and encompassed present-day Warner Springs. The western part of the grant is under the waters of Lake Henshaw, formed in 1922 by a dam on the San Luis Rey River.