[1] Under Spain, no private land ownership was allowed, so the grants were more akin to free leases.Following the Mexican–American War, the 1848 Treaty of Guadalupe Hidalgo provided that the land grants would be honored.From 1773 to 1836, the border between Alta California and Baja California was about 30 miles south of the Mexico–United States border drawn by the Treaty of Guadalupe Hidalgo that ended the Mexican–American War in 1848.The result of the shifting borders is that some of the ranchos in this list, created by pre-1836 governors, are located partially or entirely in a 30-mile-wide sliver of the former Alta California that is now in Mexico rather than in the U.S. state of California.Since those ranchos remained in Mexico, in today's Mexican state of Baja California, the grants were not subject to review by the Public Land Commission except for Rancho Tijuan that had claimed part of its lands were on the American side of the border.
Mexican land grants of Tehama County, California (Bureau of Land Management map, 1997)