Rancho Cucamonga was a 13,045-acre Mexican land grant in present-day San Bernardino County, California, given in 1839 to the dedicated soldier, smuggler and politician Tiburcio Tapia by Mexican governor Juan Bautista Alvarado. The grant formed parts of present-day California cities Rancho Cucamonga and Upland. It extended easterly from San Antonio Creek to what is now Hermosa Avenue, and from today's Eighth Street to the mountains.