Alamosa County

Alamosa County is a county in southern Colorado with mountains, valleys, and protected natural areas spread across the San Luis Valley. The landscape shifts between high plains and mountain ranges that define the region's character.

The county was created in 1913 when the Colorado legislature separated the northwestern part of Costilla County to form a new administrative district. This establishment marked an important moment in how the San Luis Valley region was organized.

The name Alamosa comes from Spanish and means cottonwood tree, reflecting the trees that line the Rio Grande throughout the valley. This vegetation shapes how the landscape looks and feels to visitors passing through.

The area is accessible through major highways including US Highway 160 and US Highway 285 that connect to neighboring regions. Keep in mind that the location in a mountain region and spread-out landscape mean longer travel times between different sites.

The area contains sections of Great Sand Dunes National Park, which has some of North America's highest sand formations within a protected natural area. These unusual dunes formed over thousands of years and stand out dramatically against the surrounding mountain landscape.

Location: Colorado

Inception: March 8, 1913

Capital city: Alamosa

Shares border with: Saguache County, Huerfano County, Costilla County, Conejos County, Rio Grande County

Website: http://alamosacounty.org

GPS coordinates: 37.57000,-105.78000

Latest update: December 14, 2025 20:26