Birds & Science >

Alamosa County
Size: 10,000 acres
Elevation: 7600 feet

Habitats:
Wetlands, open water, semidesert shrubland

Ownership:
State (CO State Parks, CO Division of Wildlife)

Land Use:
Primary – tourism/recreation, nature and wildlife conservation, hunting/fishing, water supply, waterfowl production

IBA Criteria: 2, 4 (waterfowl, heronries, shorebirds, gulls/terns, raptors)

Site description

Location:
San Luis Lakes State Park and Wildlife Area is located in the San Luis Valley near the town of Mosca, in south-central Colorado.

Vegetative/natural features:
The site includes an 890 surface-acre playa lake amid rolling sandhills and alkaline flats. Uplands are dominated by saline botton land shrublands, cold desert shrublands, and salt meadows. Common plant species include greasewood, rubber and Greene rabbitbrush, four-wing saltbrush, yucca, western wheatgrass, alkali cordgrass, saltgrass, Indian ricegrass, needle-and-thread grass, sandhills muhley, and blue grama. Diverse wetland and aquatic plant communities have become established around and in the playa.

Ornithological Importance

This site represents one of the few areas in the San Luis Valley with a large body of water that is significant as a migration resting area for shorebirds, waterbirds, gulls, and terns. It provides a rich food source that allows migrating species to recharge food reserves before continuing migration. Over 2,000 waterfowl use the site during migration. Its alkali lakes and wetlands provide excellent habitat for shorebirds. Numerous rare migrants have occurred here, including Tricolored Heron, Barrow’s Goldeneye, Least Bittern, White-rumped Sandpiper, and Peregrine Falcon.

The site used to be breeding habitat for Snowy Plovers. Each year after spring runoff, alkali mudflats would expand as water evaporated. The Closed Basin project destroyed that habitat by turning San Luis Lake into a water storage facility. Snowy Plovers have not been seen there since 1984.

Conservation/Management Issues

Serious threats:

• hydrologic changes;
• disturbance to birds from recreational use (motorboats, jetskis).

Management details:
The site is managed by Lathrop State Park, with involvement by the Colorado Division of Wildlife. It is a Colorado Watchable Wildlife site.