Navajo State Park, State park with reservoir in Archuleta County, US.

Navajo State Park protects a 15,000-acre reservoir on the San Juan River, which begins in Colorado's San Juan Mountains and runs 20 miles into New Mexico, with 150 miles of shoreline in two states. The Piedra River joins near the northern boundary. Uplands are flat-topped mesas and rolling hills of Eocene sandstone and conglomerate, cut by steep-sided canyons.

The area was home to Ancestral Puebloans, who left around 1050 A.D. during a severe drought; Ute and Navajo peoples settled it in the 14th century. The Dominguez-Escalante Expedition's ten explorers were among the first white men here, seeking a route from New Mexico to California. The Denver and Rio Grande Western Railroad laid tracks in the early 1880s and served the area until 1967. Navajo Dam, built in 1962, supplied irrigation water for the Navajo Nation.

The reservoir's name comes from the Navajo Dam, finished in 1962 to supply irrigation water for the Navajo Nation. Ancestral Puebloans lived here until about 1050 A.D., when a severe drought drove them out; Ute and Navajo people settled the area in the 14th century. The Dominguez-Escalante Expedition's ten explorers were among the first white men to enter.

The park provides camping areas, cabin lodging, and a marina with boat rentals and fuel services for water activities. Plan your visit during late summer through early fall when weather conditions are most favorable for outdoor recreation.

The park spans across state lines into New Mexico, creating one of the largest water recreation areas in the region. This boundary-crossing feature makes it a rare destination where two states share a single body of water.