Though livestock was introduced to the Southwest in the 1500s by the Spanish, the first domestic animals were not brought to the Glen Canyon area until 1776 when the Dominquez-Escalante expedition led cattle across the Colorado River at Padre Bay at “Crossing of the Fathers,” now under the deep water of Lake Powell. The first serious attempts at using the range were in the 1860s, when the introduction of sheep to nearby Kanab, Utah was recorded. Settlers brought small numbers of livestock to the area in the early 1870s. In 1890, nearly 20,000 animals were recorded using the area. The following years were dry, and livestock numbers decreased due to drought and overgrazing. This decline continued through the 1900, when only 9,800 cattle were recorded in San Juan County.
During hard economic times in the early 1900s, sheep began to replace cattle and in 1913, 110,000 sheep and 15,000 cattle were recorded in Kane County. Livestock numbers increased briefly during World War I, but returned to declining trends in the 1920s. Prior to the 1930s, overgrazing severely degraded the land, compacting newly barren soil and changing fire regimes by reducing or eliminating grassy fuel. Riparian areas that supported diverse vegetation and wildlife were trampled, eroding banks and decreasing water quality. Springs, which are important sources of water for wildlife, were badly trampled, with loss of wetland plants and soils. The Taylor Grazing Act of 1934 helped restore many areas from previous damage by regulating grazing on federal public land. Cattle eventually replaced sheep on the landscape by 1974 when 5,500 sheep and 8,100 cattle were recorded in Kane County. Glen Canyon NRA was historically grazed by sheep, though there are no domestic sheep in the area at this time.