The Tierra Amarilla Land Grant in northern New Mexico and southern Colorado consists of 594,516 acres (2,405.92 km2) of mountainous land. The government of New Mexico awarded it to Manuel Martinez and his offspring in 1832. The grant was settled by Hispanics in the 1860s and the original inhabitants, the Ute Indians, were induced to leave. Settlers were given small plots, but most of the land in the grant area was designated as common land for the use of all the settlers and their descendants. After its conquest of New Mexico in 1846, the United States government upheld the validity of the grant, but subsequent actions by the U.S. did not protect the right to access common lands by the settlers. Politician and land speculator Thomas Catron, a member of the Santa Fe Ring, acquired nearly all the land by 1883 but later sold it to a development company. Access to the common lands of the grant by the Hispanic settlers and their descendants gradually disappeared as the common land became owned by Anglo ranchers, development companies, and speculators.

Thomas Benton Catron was an American politician and lawyer who was influential in the establishment of the U.S. state of New Mexico, and served as one of its first United States Senators. Catron has defenders but enemies have described him as a "greedy land grabber and ruthless politico."