|San Luis Hills|
|Elevation||2,806 m (9,206 ft)|
|Area||428 sq mi (1,110 km2)|
|Location||San Luis Valley|
The San Luis Hills 9,206 feet (2,806 meters)are a group of small mountain ranges in Conejos and Costilla counties in the San Luis Valley in southern Colorado. The individual mountain ranges that make up the San Luis Hills include the Fairy Hills, the Brownie Hills, the Piñon Hills, and the South Piñon Hills. The San Luis Hills' highest point is Flat Top, elevation
Each of the separate mountain ranges includes flat-topped mesas and hills, and the ranges trend from the southwest to the northeast. 7,500 feet (2,300 meters) in elevation, they appear more as hills than mountains, despite rising to eight or nine thousand feet above sea level.Because the individual hills rise from the floor of the San Luis Valley, which is about
The Hills are all within the Sangre de Cristo National Heritage Area.
The Fairy Hills lie at. They are north of Colorado State Highway 142 and west of the Rio Grande in Conejos County.
The Brownie Hills lie at. They are north of Colorado State Highway 142 and east of the Rio Grande, in Costilla County.
The Piñon Hills lie at. They are south of Colorado State Highway 142 and west of the Rio Grande, in Conejos County.
The South Piñon Hills lie at. As their name indicates, they are south of the Piñon Hills in Conejos County, and just north of the New Mexico border.
The hills are the exposed parts of an intra-rift horst. They are capped by Miocene basalts of the Hinsdale Formation.The basalt is underlain by Oligocene andesite and dacite volcanic deposits of the lower Conejos Formation.
The public lands in the San Luis Hills are not developed for recreation. However, some informal hiking trails exist, and mountain climbing and bouldering are possible, especially around the Manassa Dike on south side of Flat Top.
The San Luis Hills Wilderness Study Area occupies a 10,883-acre (4,404-hectare) tract of land in the Piñon Hills. The wilderness study area was established in 1980 and is owned by the Bureau of Land Management.
In 2016, the Western Rivers Conservancy got funding from the Conservation Alliance to purchase a 17,019-acre (6,887-hectare) tract in the Brownie Hills on both sides of the Rio Grande, some of it adjacent to or overlapping with the Rio Grande Natural Area. The plan is to transfer the land to Costilla County, which will manage it for wildlife habitat, agriculture, and public open space.
The San Luis Valley is a region in south-central Colorado with a small portion overlapping into New Mexico. The Rio Grande with headwaters in the San Juan Mountains about seven miles east of Silverton, Colorado flows through the San Luis Valley and then south into New Mexico. It contains 6 counties and portions of 3 others. The San Luis Valley was ceded to the United States by Mexico following the Mexican–American War. Hispanic settlers began moving north and settling in the valley after the United States made a treaty with the Utes and established a fort. Prior to the Mexican war the Spanish and Mexican governments had reserved the valley to the Utes, their allies. During the 19th century Anglo settlers settled in the valley and engaged in mining, ranching, and irrigated agriculture. Today the valley has a diverse Anglo and Hispanic population.
Costilla County is a county located in the U.S. state of Colorado. As of the 2010 census, the population was 3,524. The county seat is San Luis, the oldest continuously occupied town in Colorado.
Alamosa County is a county located in the U.S. state of Colorado. As of the 2010 census, the population was 15,445. The county seat is Alamosa. The county name is the Spanish language word for a "grove of cottonwood trees."
Antonito is a Statutory Town located in Conejos County, Colorado, United States. The town population was 781 at the 2010 United States Census.
The Town of Manassa is the Statutory Town that is the most populous municipality in Conejos County, Colorado, United States. The town population was 991 at the 2010 United States Census.
The Town of Blanca is a Statutory Town in Costilla County, Colorado, United States. The town population was 385 at the 2010 census.
The Town of San Luis is a statutory town that is the county seat and the most populous town of Costilla County, Colorado, United States. Formerly known as San Luis de la Culebra, San Luis is the oldest continuously occupied town in Colorado. The population was 629 at the 2010 census.
The Conejos River is a tributary of the Rio Grande, approximately 92.5 miles (148.9 km) long, in south-central Colorado in the United States. It drains a scenic area of the eastern San Juan Mountains west of the San Luis Valley.
The Alamosa National Wildlife Refuge is an 11,169-acre (4,520 ha) United States National Wildlife Refuge located in southern Colorado. The site is located in the San Luis Valley along the east side of the Rio Grande approximately 8 miles (13 km) southeast of Alamosa primarily in southeastern Alamosa County, although very small parts extend into northeastern Conejos and western Costilla counties. It is managed by the United States Fish and Wildlife Service jointly with the Baca and Monte Vista National Wildlife Refuges. It was established in 1962 as a haven for migratory birds and other wildlife.
Chama is an unincorporated community and U.S. Post Office in Costilla County, Colorado, United States. The ZIP Code of the Chama Post Office is 81126.
Garcia is an unincorporated community located in Costilla County, Colorado, United States. The San Luis post office (Zip Code 81152) serves Garcia postal addresses.
San Pablo is an unincorporated community located in Costilla County, Colorado, United States. The San Luis post office (Zip Code 81152) serves San Pablo postal addresses.
Mesita is an unincorporated community located in Costilla County, Colorado, United States. The San Luis post office (Zip Code 81152) serves Mesita postal addresses.
Lasauses or Los Sauces is a populated place in Conejos County, Colorado, United States, on the west side of the Rio Grande.
Bountiful is an unincorporated community in Conejos County, in the U.S. state of Colorado.
Rio San Antonio is a tributary of the Conejos River in northern New Mexico and southern Colorado. Via the Conejos River, it is part of the upper Rio Grande system. The river is used extensively for irrigation in its lower course through the southern San Luis Valley.
Lake Alamosa is a former lake in Colorado. It existed from the Pliocene to the middle Pleistocene in the San Luis Valley, fed by glacial meltwater from surrounding mountain ranges. Water levels waxed and waned with the glacial stages until at highstand the lake reached an elevation of 2,335 meters (7,661 ft) and probably a surface of over 4,000 square kilometers (1,500 sq mi), but only sparse remains of the former waterbody are visible today. The existence of the lake was postulated in the early 19th century and eventually proven in the early 20th century.
The Servilleta Basalt or Servilleta Formation is a geologic formation that underlies most of the Taos Plateau of northern New Mexico. It has a radiometric age of 3.6 to 4.5 million years, corresponding to the Pliocene epoch.
The Hinsdale Formation is a geologic formation exposed in southwestern Colorado and northern New Mexico. It has a radiometric age of 4.4 to 26.8 million years, corresponding to the Neogene period.