It was given in 1841 by acting Governor Manuel Jimeno to William (Julian) Pope.
William Pope (1805-1843) was born in Kentucky and became a trapper living in New Mexico. Pope went to California on the Gila route in 1827, and returned to New Mexico. In 1835, Pope and his wife Maria Juliana Salazar (1810-1900) joined an overland party led by Isaac Slover and came to Los Angeles.
William Pope joined with Cyrus Alexander, William Knight and William Gordon on a trip to the Napa Valley in 1841. They stayed at George C. Yount's home, before the four split up, each claiming a valley for his own. Pope petitioned General Vallejo and the acting governor of California, Manuel Jimeno for a two square league parcel on the east side of Howell Mountain. Juliana and the four children moved from Los Angeles and stayed at Yount's ranch while her husband built their first home on his new property. In 1843, the Pope family moved wagons and livestock from Yount's ranch to their adobe house. But William Pope died in an accident in 1843.
With the cession of California to the United States following the Mexican-American War, the 1848 Treaty of Guadalupe Hidalgo provided that the land grants would be honored. As required by the Land Act of 1851, a claim for Rancho Locoallomi was filed with the Public Land Commission in 1852, and the grant was patented to the heirs of William Pope (Jose Pope, María Pope, Luciana Pope, Isabella Pope, and Delavina Pope) in 1862.
Juliana Pope married neighbor Elias Barnett (1805-1880), a Missouri pioneer. Barnett had come to California in 1841 with the Bartleson-Bidwell Party. He stayed with George C. Yount until 1843, then squatted in Pope Valley, before marrying Juliana Pope.