Hispano pioneers founded Colorado's first permanent settlements as settlers pushed northward from Taos toward present Colorado in the early 1800s. In 1844, the Mexican government gave the Sangre de Cristo land grant to two Taos residents, and the Costilla area of the grant was permanently colonized in 1849. Farther north on the grant, San Luis was founded in 1851, and other settlements soon followed nearby. Because of hostile Utes and Apaches, houses were built in defensive plazas with windowless exterior walls. Fort Massachusetts, established in 1852, and its successor Fort Garland, established in 1858, were created by the U.S. Army to protect these villages, many of which developed into towns that survive today. When gold was discovered in Colorado in 1858, the well-established farms of the San Luis Valley provided produce for the new supply-starved camps. Today the valley remains an important agricultural area of the state.