Mount McLoughlin, the highest point in the Rogue River watershed
Draining 5,156 square miles (13,350 km2), the Rogue River watershed covers parts of Jackson, Josephine, Curry, Douglas, and Klamath counties in southwestern Oregon and Siskiyou and Del Norte counties in northern California. The steep, rugged basin, stretching from the western flank of the Cascade Range to the northeastern flank of the Siskiyou Mountains, varies in elevation from 9,485 feet (2,891 m) at the summit of Mount McLoughlin in the Cascades to 0 feet (0 m), where the basin meets the ocean. The basin borders the watersheds of the Williamson River, Upper Klamath Lake, and the upper Klamath River on the east; the lower Klamath, Smith, and Chetco rivers on the south; the North Umpqua, South Umpqua, Coquille, and Sixes rivers on the north, and the Pacific Ocean on the west.
In 2000, Jackson County had a population of about 181,300, most of them living in the Bear Creek Valley cities of Ashland (19,500), Talent (5,600), Phoenix (4,100), Medford (63,200), Central Point (12,500), and Jacksonville (2,200). Others in Jackson County lived in the cities of Shady Cove (2,300), Eagle Point (4,800), Butte Falls (400) and Rogue River (1,800). Josephine County had a population of 75,700, including the cities of Grants Pass (23,000) and Cave Junction (1,400). Gold Beach (1,900) is the only city in Curry County (21,100) in the Rogue River basin. Only small, sparsely inhabited parts of the watershed are in Klamath and Douglas counties in Oregon and Siskiyou and Del Norte counties in California. The watershed's average population density is about 32 people per square mile (12.4/km2).
Cattle graze near Grants Pass. About six percent of the watershed is devoted to farming.
Many overlapping entities including city, county, state, and federal governments share jurisdiction for parts of the watershed. About 60 percent of the basin is publicly owned and is managed by the United States Forest Service, the Bureau of Land Management (BLM), and the United States Bureau of Reclamation. Under provisions of the federal Clean Water Act, the Environmental Protection Agency (EPA), assisted by the Oregon Department of Environmental Quality (DEQ) and other agencies in both states, is charged with controlling water pollution in the basin. United States National Forests and other forests cover about 83 percent of the basin; another 6 percent is grassland, 3 percent shrub, and only 0.2 percent wetland. Urban areas account for slightly less than 1 percent and farms for about 6 percent.
Precipitation in the Rogue basin varies greatly from place to place and season to season. At Gold Beach on the Pacific Coast it averages about 80 inches (2,000 mm) a year, whereas at Ashland, which is inland, it averages about 20 inches (510 mm). The average annual precipitation for the entire basin is about 38 inches (970 mm). Most of this falls in winter and spring, and summers are dry. At high elevations in the Cascades, much of the precipitation arrives as snow and infiltrates permeable volcanic soils; snowmelt contributes to stream flows in the upper basin during the dry months. Along the Illinois River in the lower basin, most of the precipitation falls as rain on shallow soils; rapid runoff leads to high flows during winter storms and low flows during the dry summer. Average monthly temperatures for the whole basin range from about 68 °F (20 °C) in July and August to about 40 °F (4 °C) in December. Within the basin, local temperatures vary with elevation.