The Great Basin can be defined floristically by plant communities dominated by species of sagebrush (Artemisia) and saltbush (Atriplex) in its southern portions and in its northern portions by sagebrush steppe and woodlands dominated by juniper (Juniperus). By this definition, nearly 7.4 million acres (3 million ha) of Great Basin sagebrush steppe exists in the coterminous United States. It can also be defined hydrologically as the area in the Western United States that is internally drained; in other words, with a few exceptions, precipitation does not ultimately flow to the oceans, but remains in the basin (USGS 2016). The hydrologic definition is somewhat smaller in area, but important for restoration purposes (Svejcar et al. 2017). Studies clearly show that the sagebrush steppe has been in a continued state of change for many years. Portions of the Lassen and Modoc National Forests (hereafter the Lassen and the Modoc) occur in the northern portion of the Great Basin, which contains the unique Modoc Plateau subregion.