Rancho Temescal was a Mexican land grant in present-day Ventura County and Los Angeles County, California given in 1843 by Governor Manuel Micheltorena to Francisco Lopez and José Arellanes. The word Temescal is Spanish for sweat bath or sweat lodge. The grant was located in the upper end of the Santa Clara Valley, in the eastern section of Ventura County, in the upper Santa Clara River Valley near the base of the Topatopa Mountains where Piru Creek and the Santa Clara River meet. The grant encompassed present-day Lake Piru and town of Piru.