William Wolfskill (1798–1866) was an American-Mexican pioneer, cowboy, and agronomist in Los Angeles, California beginning in the 1830s. He had earned money for land in a decade as a fur trapper near Santa Fe, New Mexico, where he had become a Mexican citizen. This enabled him to own land in California. Wolfskill was highly influential in the development of California's agricultural industry in the 19th century, establishing an expanded viticulture and becoming the largest wine producer in the region. One of the wealthiest men for his time, he expanded his holdings, running sheep and cultivating oranges, lemons and other crops. He is credited with establishing the state's citrus industry and developing the Valencia orange. It became the most popular juice orange in the United States and was the origin of the name of Valencia, California. With his brother John Reid Wolfskill, in 1842 William bought a large parcel in the Sacramento Valley; they called this Rancho Rio de los Putos, later known as the Wolfskill Ranch. The brothers later divided this land, near what is now Winters, California. There John Wolfskill established orchards and vineyards. Three other Wolfskill brothers migrated to California, working first with John in the north. History Wolfskill moved to New Mexico in 1821, while the region was a province of Mexico called Santa Fe de Nuevo México. He spent ten years fur trapping in the New Mexico area, as the fur trade was highly lucrative and he could put together a stake for his future. In 1828 he became a naturalized Mexican citizen. Wolfskill left Taos, New Mexico, in September 1830 with a party of mountain men that included George C. Yount. When they arrived in Southern California in early 1831 (using the trail Jedediah Smith had mapped across the Mojave desert), Wolfskill and Yount went to the coast to hunt sea otter. Wolfskill eventually returned to Southern California while Yount decided to go north, and the two parted company. Yount settled in the Napa Valley. As a naturalized citizen of Mexico, Wolfskill was allowed to own land and bought a parcel where downtown Los Angeles later developed. He began to cultivate grapevines for wine. He eventually planted 32,000 vines on a 48-acre vineyard. Initially, he planted mission vines, which had been introduced by the Spanish missionaries. He expanded his plantings to include other varietals later. In May 1842 Wolfskill was awarded a large land grant