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Photographs of archaeological sites with physical degradation from erosion along the Colorado River, Grand Canyon National Park

May 2023 (approx.)

Detailed Description

Photographs of different types of erosion that physically degrade archaeological sites along the Colorado River in Grand Canyon National Park: (A) Cutbank erosion in a large alluvial terrace has exposed a prehistoric hearth (buried charcoal lens) in profile; (B) Surface erosion from both water runoff and wind has deflated the archaeological matrix, and in the absence of burial by sand, exposed the rim of a prehistoric bowl; (C) A small gully adjacent to upright slabs forming the base course of a stone and adobe structure; (D) The surface of a roasting feature where wind deflation, coupled with an absence of new sand, has resulted in the loss of the archaeological matrix that once surrounded the fire-altered rock. All photos by Jennifer Dierker, National Park Service, used with permission.

This figure was published in the paper, "Archaeological sites in Grand Canyon National Park along the Colorado River are eroding owing to six decades of Glen Canyon Dam operations," available at


Public Domain.