The Damage Done to Canyon of the Ancients National Monument by Livestock Grazing

Lowry Ruins in southwest Colorado Canyons of the Ancients NM, CO. George Wuerthner.

Livestock grazing threatens the integrity of Colorado’s Canyon of the Ancients National Monument. Located in SW Colorado near Cortez,  President Clinton established the 176,000 acre Monument in 2000 to protect one of the highest concentrations of archeological sites in the West representing the Archaic to the Pueblo periods. These archeological resources include cliff dwellings, rock art, and other evidence of past human occupation. More than 5000 archeological sites have been recorded, and undoubtedly there are thousands more to uncover.

The Monument also contains four wilderness study areas and is listed on the National List of Historic Places.


Paleo-Indians occasionally used the area up to 7,500 BC. The following six thousand years was the Archaic period when hunters and gatherers dominated the Canyons of the Ancients area.

Then starting around 1500 BC, the Basketmakers began to move into the area to be followed by the Pueblo people around 750 AD, who resided in the area until about 1300 AD.

The Pueblo people brought agricultural practices, likely from the south in Mexico. With agriculture, a more sedentary year-round occupation was possible. During this period, the famous cliff houses scattered around the Four Corners area came into existence.

The last phase of the Pueblo 111 era (1150-1300 AD) is when large multi-story and room houses were established like those seen at nearby Mesa Verde National Park.

One of the many archeological sites within the monument. Photo George Wuerthner.

However, agriculture led to population increases, which forced Pueblo people to colonize increasingly marginal habitat. In addition, the overcutting of trees for firewood and structures, combined with soil depletion, eventually led to greater conflicts.

Starting in the 11th century, there began to be evidence of violent deaths likely related to internal struggles. By the 13th century, there was evidence of warfare.

For instance, at Castle Rock, there is evidence of a massacre of at least 41 people and possible cannibalism within the Monument.

The final straw to break the proverbial camel’s back was a severe decades-long drought. The Pueblo people were forced to abandon their canyon homes and migrated to year-round reliable water sources like the Rio Grande River in New Mexico, where their descendants still live.

The area is also home to unusual and relatively rare species like the Mesa Verde night snake, long-nosed leopard lizard, and twin-spotted spiny lizard in the area north of Yellow Jacket Canyon.


Like many BLM national monuments,  the designation language permits livestock grazing to continue. However, grazing can not impact the primary purposes of the Monument, which in this case is the protection of archeological sites.

Cattle grazing in this arid canyon country is impossible to do without significant damage to other public values including soils, plants, wildlife and archeological treasures. Photo George Wuerthner

What place does cattle grazing have with national and international archeological riches? If there is even the slightest chance that livestock will damage sites, cattle grazing should be prohibited. I have personally witnessed cattle knocking over ancient walls, trampling pottery, and damaging these irreplaceable treasures.

There are 23 grazing allotments in the Monument, and 90% of the Monument is under grazing pressure. Since 2005, two allotments–the Yellow Jacket and Flodine Grazing Allotments-have been vacant and since 2015 the BLM has considered, but has not authorized restocking these allotments. The BLM planned to reissue the grazing permits five years ago, but opposition from environmental and tribal interests resulted in a new analysis.

It’s another example of where federal agencies appear to promote grazing by reopening vacant allotments to renewed grazing.

In 2015 Advocates for the West filed a protest on behalf of environmental groups against the Bureau of Land Management’s proposed decision to issue new 10-year grazing permits. The groups opposing the restoration of livestock grazing include Great Old Broads for Wilderness, WildEarth Guardians, Western Watersheds Project, Sierra Club, Wildlands Defense, Grand Canyon Trust, and Natural Resources Defense Council.

The issue of grazing entails more than just damage to archeological sites. Biocrusts are common in the sandy soils of the Monument. A study of grazing impacts on biological soil crusts found that crusts were recovering in portions of the Monument where livestock grazing was excluded. Some biocrusts have tiny root-like filaments that hold soils together and reduce erosion. They can also trap atmospheric nitrogen and enrich the soils.

Other impacts attributed to livestock grazing noted were an increase in cheatgrass, an exotic annual that is highly flammable, and one of the factors contributing to the loss of native plants. Also noted was knapweed, another alien whose spread is facilitated by livestock trampling.

Yellow Jacket Creek is one of the perennial streams in the Monument home to rare fish species and can be impacted by livestock grazing.

Given the incredible archeological values of the area and its natural values, continued livestock grazing in this sensitive area amounts to legalized vandalism.

George Wuerthner has published 36 books including Wildfire: A Century of Failed Forest Policy