The Southern Cascades ecoregion is lower in elevation and less rugged than the surrounding regions and is characterized by gently sloping mountains and broad valleys. Elevation varies from 1,400 to 5,300 feet (430 to 1,620 m). The climate is drier than other parts of the Cascades, and the vegetation reflects the long summer drought. River and stream discharge are also significantly lower than in systems to the north. Western hemlock and western red cedar, which are indicator species in the Western Cascades ecoregions, decline southward in the Southern Cascades, and are replaced by Sierra Nevada species such as California incense-cedar, white fir, Shasta red fir, and sugar pine, with an understory of snowberry, twinflower, Oregon grape, serviceberry, golden chinkapin, and oceanspray. At lower elevations, Douglas-fir and ponderosa pine are prevalent. The region covers 1,414 square miles (3,660 km2) in Southern Oregon, in the South Umpqua and Rogue River watersheds, separated from the Western Cascades by the Calapooya Divide.