The Rogue River (, ) in southwestern Oregon in the United States flows about in a generally westward direction from the Cascade Range to the Pacific Ocean. Known for its salmon run, whitewater rafting, and rugged scenery, it was one of the original eight rivers named in the Wild and Scenic Rivers Act of 1968. Beginning near Crater Lake, which occupies the caldera left by the explosive volcanic eruption and collapse of Mount Mazama, the river flows through the geologically young High Cascades and the older Western Cascades, another volcanic province. Further west, the river passes through multiple exotic terranes of the more ancient Klamath Mountains. In the Kalmiopsis Wilderness section of the Rogue basin are some of the world's best examples of rocks that form the Earth's mantle. Near the mouth of the river, the only dinosaur fragments ever discovered in Oregon were found in the Otter Point Formation, along the coast of Curry County.
People have lived along the Rogue River and its tributaries for at least 8,500 years. European explorers made first contact with Native Americans (Indians) toward the end of the 18th century and began beaver trapping and other activities in the region. Clashes, sometimes deadly, occurred between the natives and the trappers and later between the natives and European-American miners and settlers. These struggles culminated with the Rogue River Wars of 1855–56 and removal of most of the natives to reservations outside the basin. After the war, settlers expanded into remote areas of the watershed and established small farms along the river between Grave Creek and the mouth of the Illinois River. They were relatively isolated from the outside world until 1895, when the Post Office Department added mail boat service along the lower Rogue. As of 2010, the Rogue has one of the two remaining rural mail-boat routes in the United States.
Dam building and removal along the Rogue has generated controversy for more than a century; an early fish-blocking dam (Ament) was dynamited by vigilantes, mostly disgruntled salmon fishermen. By 2010, all of the main-stem dams downstream of a huge flood-control structure from the river mouth had been removed. Aside from dams, threats to salmon include high water temperatures. Although sometimes too warm for salmonids, the main stem Rogue is relatively clean, ranking between 85 and 97 (on a scale of 0 to 100) on the Oregon Water Quality Index (OWQI).
Although the Rogue Valley near Medford is partly urban, the average population density of the Rogue watershed is only about 32 people per square mile (12 per km2). Several historic bridges cross the river near the more populated areas. Many public parks, hiking trails, and campgrounds are near the river, which flows largely through forests, including national forests. Biodiversity in many parts of the basin is high; the Klamath-Siskiyou temperate coniferous forests, which extend into the southwestern Rogue basin, are among the four most diverse of this kind in the world.
Course
The Rogue River begins at Boundary Springs on the border between Klamath and Douglas counties near the northern edge of Crater Lake National Park. Although it changes direction many times, it flows generally west for from the Cascade Range through the Rogue River–Siskiyou National Forest and the Klamath Mountains to the Pacific Ocean at Gold Beach. Communities along its course include Union Creek, Prospect, Trail, Shady Cove, Gold Hill and Rogue River, all in Jackson County; Grants Pass and Galice in Josephine County; and Agness, Wedderburn and Gold Beach in Curry County. Significant tributaries include the South Fork Rogue River, Elk Creek, Larson Creek, Bear Creek, the Applegate River, and the Illinois River. Arising at above sea level, the river loses more than in elevation by the time it reaches the Pacific.Google Earth elevation for GNIS coordinates It was one of the original eight rivers named in the National Wild and Scenic Rivers Act of 1968, which included of the Rogue, from west of Grants Pass to east of the mouth at Gold Beach. In 1988, an additional of the Rogue between Crater Lake National Park and the unincorporated community of Prospect was named Wild and Scenic. Of the river's total length, , about 58 percent is Wild and Scenic. The Rogue is one of only three rivers that start in or east of the Cascade Range in Oregon and reach the Pacific Ocean. The others are the Umpqua River and Klamath River. These three Southern Oregon rivers drain mountains south of the Willamette Valley; the Willamette River and its tributaries drain north along the Willamette Valley into the Columbia River, which starts in British Columbia rather than Oregon.
Discharge
The United States Geological Survey (USGS) operates five stream gauges along the Rogue River. They are located, from uppermost to lowermost, near Prospect, Eagle Point, Central Point, Grants Pass, and Agness. Between 1960 and 2007, the average discharge recorded by the Agness gauge at river mile (RM) 29.7 or river kilometer (RK) 47.8 was . The maximum discharge during this period was on December 23, 1964, and the minimum discharge was on July 9 and 10, 1968. This was from a drainage basin of , or about 76 percent of the entire Rogue watershed. The maximum flow occurred between December 1964 and January 1965 during the Christmas flood of 1964, which was rated by the National Weather Service as one of Oregon's top 10 weather events of the 20th century.
Watershed
Draining , 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 at the summit of Mount McLoughlin in the Cascades to , 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 Rogue River 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).
Many overlapping entities, including the 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 a year, whereas at Ashland, which is inland, it averages about . The average annual precipitation for the entire basin is about . 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 in July and August to about in December. Within the basin, local temperatures vary with elevation.
Geology High and Western Cascades Arising near Crater Lake, the Rogue River flows from the geologically young High Cascades through the somewhat older Western Cascades and then through the more ancient Klamath Mountains. The High Cascades are composed of volcanic rock produced at intervals from about 7.6 million years ago through geologically recent events such as the catastrophic eruption of Mount Mazama in about 5700 BCE. The volcano hurled of ash into the air, covering much of the western U.S. and Canada with airfall deposits. The volcano's subsequent collapse formed the caldera of Crater Lake.
Older and more deeply eroded, the Western Cascades are a range of volcanoes lying west of and merging with the High Cascades. They consist of partly altered volcanic rock from vents in both volcanic provinces, including varied lavas and ash tuffs ranging in age from 0 to 40 million years. As the Cascades rose, the Rogue maintained its flow to the ocean by down-cutting, which created steep narrow gorges and rapids in many places. Bear Creek, a Rogue tributary that flows south to north, marks the boundary between the Western Cascades to the east and the Klamath Mountains to the west.
Klamath Mountains Much more ancient than the upstream mountains are the exotic terranes of the Klamath Mountains to the west. Not until plate tectonics separated North America from Europe and North Africa and pushed it westward did the continent acquire, bit by bit, what became the Pacific Northwest, including Oregon. The Klamath Mountains consist of multiple terranes—former volcanic islands and coral reefs and bits of subduction zones, mantle, and seafloor—that merged offshore over vast periods before colliding with North America as a single block about 150 to 130 million years ago. Much of the Rogue River watershed, including the Rogue River canyon, the Kalmiopsis Wilderness, the Illinois River basin, and Mount Ashland, is composed of exotic terranes.
Among the oldest rocks in Oregon, some of the formations in these terranes date to the Triassic, nearly 250 million years ago. Between 165 and 170 million years ago, in the Jurassic, faulting consolidated the Klamath terranes offshore during what geologists call the Siskiyou orogeny. This three- to five-million-year episode of intense tectonic activity pushed sedimentary rocks deep enough into the mantle to melt them and then forced them to the surface as granitic plutons. Belts of plutons, which contain gold and other precious metals, run through the Klamaths and include the Ashland pluton, the Grayback batholith east of Oregon Caves National Monument, the Grants Pass pluton, the Gold Hill pluton, the Jacksonville pluton, and others. Miners have worked rich deposits of gold, silver, copper, nickel, and other metals in several districts of the Klamaths. Placer mining in the mid-19th century soon led to lode mining for gold. Aside from a mine in eastern Oregon, the Greenback Mine along Grave Creek, a Rogue tributary, was the most productive gold mine in Oregon.