Livestock grazing may be the most pervasive and harmful use of the Sagebrush Sea. More than 99 percent of remaining sagebrush steppe has been affected by livestock and about 30 percent has been heavily grazed.

			The integrity of the Sagebrush Sea in parts of Wyoming, Colorado, Utah, Montana, and the Dakotas is threatened by oil and gas extraction, particularly coalbed methane development.

			Roads, fences, and utility corridors fragment wildlife habitat throughout the Sagebrush Sea. Off-road vehicle use also damages habitat and wrecks watersheds in many places across the landscape.

			Disturbance to desert soils and native vegetation from livestock grazing, fire, agriculture, off-road vehicle use, oil and gas extraction and development contributes significantly to the introduction and spread of invasive species.

			Hard rock mining occurs mostly in the Great Basin region of the Sagebrush Sea, and especially in Nevada. While employing relatively few Nevadans, national and transnational mining companies have torn gaping holes in the state that may never heal.

			Some native tree species in the Sagebrush Sea are unnaturally expanding their range into sagebrush steppe habitat due primarily to the introduction of domestic livestock grazing and the exlusion of fire.

			A combination of fire suppression, livestock grazing and the spread of non-native weeds has drastically altered the natural fire regime in the Sagebrush Sea.

			Throughout the 20th century sagebrush was removed mechanically, burnt and destroyed with chemical herbicides. Wheat and other crops, irrigated pasture and non-native forage grasses replaced sagebrush habitat.