Grazing exacts a toll on prehistoric resources found on public lands. An assessment of the Glen Canyon National Recreations Area (managed by the National park Service) noted the extensive damage cattle can cause to above-ground masonry structures:
[d]isplacement and loss of masonry elements, toppling of walls, loss of interior features and other construction details, churning of fill, and undermining of walls and foundations can all happen very quickly once a structure is exposed to livestock grazing.
The report also cited evidence of widespread damage to surface and subsurface artifact concentrations, middens, and even pictographs and petroglyphs - all caused by livestock grazing. According to survey data from one plot in the National Recreation Area, grazing had impacted 86 percent of the recorded prehistoric sites. Despite the documented damage to cultural resources caused by cattle grazing, the BLM continues to renew the leases of grazing allotments in culturally rich areas with little or no monitoring or mitigation. To make matters worse, the BLM periodically attempts to improve grazing conditions by uprooting the native pinyon-juniper vegetation using an enormous chain suspended between two bulldozers. These so-called "vegetation treatments" not only scar the land, they displace and pulverize any cultural artifacts as well.
|"It is common to find sites where structures
are visible only as chunks of mortar scattered among the dung, with perhaps
a tell-tale stain of clay along an alcove back wall to indicate a structure
once stood there. Wherever livestock have access, surface artifacts are
rare. The integrity of artifact concentrations is lost, and the artifacts
themselves are not visible unless subsurface testing is done."
National Park Service. 1999. Glen Canyon National Recreation Area Grazing
Component and Environmental Assessment. USDI-NPS, Intermountain Region:
Paraphrased and excerpted from Southern Utah Wilderness Alliance. 2002. Preserving Prehistory. SUWA. Salt Lake City, UT: 16 (citations omitted).
See also Public Employees for Environmental Responsibility, Ruined Relics: Crumbling Cultural Resource Protection in Las Padres National Forest