Mesa Verde National Park: Cliff Dwellings Shaped by Springs

Cliff Palace. Image from the National Park Service's page.

The park

Mesa Verde National Park lies in Montezuma County in southwestern Colorado, near the Four Corners, where Arizona, Colorado, New Mexico and Utah meet. Established on June 29, 1906, it covers about 21,240 hectares (52,485 acres) of archeological landscape, with more than 600 well-preserved prehistoric cliff dwellings and more than 5,000 archeological sites.

Ancestral Puebloans lived in the region from about 550 to 1300 CE. Sites across the park that show their culture include the Far View Sites, the Mesa Top Loop, Step House, the Badger House Community on Wetherill Mesa, Cliff Palace, Balcony House, Long House and Spruce Tree House. About 32 km (20 mi) of hiking trail runs through the park. For its cultural resources, Mesa Verde was among the first places named a UNESCO World Heritage Cultural Site, on September 6, 1978.

The mesa and its rocks

The park takes in roughly 210 km² (81 mi²) of Mesa Verde itself, a broad, flat-topped mesa on the Colorado Plateau cut by many steep-sided canyons running north–south.

Why the dwellings are where they are

The Menefee Formation lets water through less easily than the Cliff House Sandstone above it. Groundwater therefore travels along the contact between the two and comes out as springs and seeps in the canyon walls. Those springs and seeps produced the alcoves, and because they were an important source of water, the Ancestral Puebloans built their cliff dwellings there. The dwellings may have started as caves or alcoves that the Puebloans sometimes later altered to live in.

Fossils

The region is highly fossiliferous: the Western Interior Seaway covered it until the end of the Cretaceous. Fossils have been documented from the Mancos Shale, the Point Lookout Sandstone and the Menefee Formation, including:

• plant remains;
• ammonites, pyritized clams, gastropods, bivalves and foraminifera;
• shark teeth, and fish bones and teeth;
• trace fossils.

All National Park Service fossils are protected under the Paleontological Resources Preservation Act of 2009, and caves under the Federal Cave Resources Protection Act of 1988.

Rockfall

Frost weathering and erosion keep working on the sandstone cliffs and can leave them unstable, and the siltstone, mudstone and shale slopes beneath erode easily. Together they make rockfall a major hazard to the park, to visitors and to cultural artifacts.

Geologic map of Mesa Verde National Park. Image from the National Park Service's Geologic Resources Inventory.

Mesa Verde belongs to the Colorado Plateaus physiographic province and shares its geologic history, and some of its characteristic formations, with a region reaching far beyond the park.

Maps and inventories

The Park Service's Geologic Resources Inventory, which produces digital geologic maps and reports for more than 270 natural resource parks, has a map and report for Mesa Verde, and a Soil Resources Inventory has been completed. Both are on the NPS DataStore.

Sources

Based on "NPS Geodiversity Atlas—Mesa Verde National Park, Colorado," National Park Service Geologic Resources Inventory, which cites National Park Service (2016), Graham (2006) and Tweet et al. (2009); a work of the United States government in the public domain.

• The atlas also says the park's boundaries include "about 1,347 km² (520 mi²)" of tableland, which cannot be squared with its stated area of about 21,240 hectares; that figure is left out here.
• The atlas writes both "Mesaverde Group" and "Mesa Verde Group"; this page uses "Mesaverde Group" throughout. The Geologic Resources Inventory report cover shown on the atlas page is not reproduced.