Because groundwater is a crucial source of fresh water, supplying the major source of drinking water for more than 50 percent of the U.S. population and 96 percent of the rural domestic supply of water, a case could be made that groundwater has a direct connection with social, economic, and ecological sustainability of rangelands. Groundwater is used for irrigated pastures that supply winter forage for livestock in many regions of the country. Many of the streams, rivers, and wet meadows in rangeland depend on groundwater and the connection between groundwater and shallow water tables. Down-cutting of mountain meadows can lower water tables and cause the replacement of water-loving vegetation with upland species.