Chimney Rock National Monument, Archaeological site and rock formations in Archuleta County, Colorado, United States

Chimney Rock National Monument covers 4,726 acres of San Juan National Forest in Archuleta County, Colorado, between Durango and Pagosa Springs. Its centerpiece is Chimney Rock, a sandstone spire about 315 feet tall, with Companion Rock beside it. On the ridge below the spires lie the excavated remains of an Ancestral Puebloan community of about 200 rooms, including a Great House Pueblo with 36 ground-floor rooms and two kivas.

Ancestral Puebloans inhabited the site between AD 925 and 1125, with roughly 2,000 people and about 200 rooms. The Great House Pueblo was begun in AD 1076 during a lunar standstill and finished in AD 1093 during another; it held 36 ground-floor rooms and two kivas. The inhabitants burned the buildings when they abandoned the site in 1125.

The name comes from the 315-foot sandstone spire beside Companion Rock. At the Great House Pueblo, two kivas and 36 ground-floor rooms served ceremonial use, and a grizzly bear jaw found in one room points to reverence for the animal; Chaco oral history holds that the Bear clan originated here. Descendants consider the site sacred and have asked the Forest Service to stop excavating.

The Visitor Center is open between May 15 and September 30, when guided walking tours run daily; outside that window access is limited. The trail to Great House Pueblo starts beside a three-room pit-house complex and climbs a ridge of sandstone bedrock, so allow time for the ascent and carry water.

In 1975 only seven breeding pairs of peregrine falcons remained in Colorado, Montana and Wyoming after DDT use. Biologist Marcy Cottrell Houle studied the pair at Chimney Rock from 1975 to 1978 for the U.S. Forest Service, and her book Wings for My Flight helped stop a million-dollar building project at the rock. Falcons now usually nest on Companion Rock.