The Willamette River is a major tributary of the Columbia River, accounting for 12 to 15 percent of the Columbia's flow. The Willamette's main stem is 187 miles (301 km) long, lying entirely in northwestern Oregon in the United States. Flowing northward between the Oregon Coast Range and the Cascade Range, the river and its tributaries form the Willamette Valley, a basin that contains two-thirds of Oregon's population, including the state capital, Salem, and the state's largest city, Portland, which surrounds the Willamette's mouth at the Columbia.
Detroit Lake is a reservoir impounded by the Detroit Dam on the North Santiam River 46 miles (74 km) southeast of Salem, Oregon, United States. The lake is adjacent to Oregon Route 22 near the city of Detroit. This mesotrophic lake stores water for use by the city of Salem and other nearby communities.
The Kentucky River is a tributary of the Ohio River, 260 miles (418 km) long, in the U.S. Commonwealth of Kentucky. The river and its tributaries drain much of the central region of the state, with its upper course passing through the coal-mining regions of the Cumberland Mountains, and its lower course passing through the Bluegrass region in the north central part of the state. Its watershed encompasses about 7,000 square miles (18,000 km2). It supplies drinking water to about one-sixth of the population of the Commonwealth of Kentucky.
The McKenzie River is a 90-mile (145 km) tributary of the Willamette River in western Oregon in the United States. It drains part of the Cascade Range east of Eugene and flows westward into the southernmost end of the Willamette Valley. It is named for Donald McKenzie, a Scottish Canadian fur trader who explored parts of the Pacific Northwest for the Pacific Fur Company in the early 19th century. As of the 21st century, six large dams have been built on the McKenzie and its tributaries.
The Dalles Dam is a concrete-gravity run-of-the-river dam spanning the Columbia River, two miles (3 km) east of the city of The Dalles, Oregon, United States. It joins Wasco County, Oregon with Klickitat County, Washington, 192 miles (309 km) upriver from the mouth of the Columbia near Astoria, Oregon. The closest towns on the Washington side are Dallesport and Wishram.
The Lewis River is a tributary of the Columbia River, about 95 miles (153 km) long, in southwestern Washington in the United States. It drains part of the Cascade Range north of the Columbia River. The drainage basin of the Lewis River covers about 1,046 square miles (2,709 km2). The river's mean annual discharge is about 6,125 cubic feet per second (173.4 m3/s). Unlike nearby Lewis County and Fort Lewis the Lewis River was not named for Meriwether Lewis, but rather for A. Lee Lewis, an early settler who homesteaded near the mouth of the river.
The Boise River is a 102-mile-long (164 km) tributary of the Snake River in the northwestern United States. It drains a rugged portion of the Sawtooth Range in southwestern Idaho northeast of Boise, as well as part of the western Snake River Plain. The watershed encompasses approximately 4,100 square miles (11,000 km2) of highly diverse habitats, including alpine canyons, forest, rangeland, agricultural lands, and urban areas.
The Payette River is an 82.7-mile-long (133.1 km) river in southwestern Idaho and is a major tributary of the Snake River.
Dworshak Dam is a concrete gravity dam in the western United States, on the North Fork Clearwater River in Clearwater County, Idaho. The dam is located approximately four miles (6 km) northwest of Orofino and impounds the Dworshak Reservoir for flood control and hydroelectricity generation. With a height of 717 feet (219 m), Dworshak is the third tallest dam in the United States and the tallest straight-axis concrete dam in the Western Hemisphere. Construction of the dam by the U.S. Army Corps of Engineers (USACE) began in 1966 and was completed in 1973.
The Bull Run River is a 21.9-mile (35.2 km) tributary of the Sandy River in the U.S. state of Oregon. Beginning at the lower end of Bull Run Lake in the Cascade Range, it flows generally west through the Bull Run Watershed Management Unit (BRWMU), a restricted area meant to protect the river and its tributaries from contamination. The river, impounded by two artificial storage reservoirs as well as the lake, is the primary source of drinking water for the city of Portland, Oregon.
Cherry Creek is a large, swift-flowing stream in the Sierra Nevada mountain range, and is the largest tributary of the Tuolumne River. The creek is 40 miles (64 km) long measured to its farthest headwaters; the main stem itself is 26 miles (42 km) long, draining a watershed of 234 square miles (610 km2) in the Stanislaus National Forest. Part of the drainage also extends into the northwest corner of Yosemite National Park.
The Crooked River is a tributary, 125 miles (201 km) long, of the Deschutes River in the U.S. state of Oregon. The river begins at the confluence of the South Fork Crooked River and Beaver Creek. Of the two tributaries, the South Fork Crooked River is the larger and is sometimes considered part of the Crooked River proper. A variant name of the South Fork Crooked River is simply "Crooked River". The Deschutes River flows north into the Columbia River.
Butte Creek is a stream in the U.S. state of Oregon, a tributary of the Pudding River. It is approximately 33 miles (53 km) long and, for all of its course, defines part of the northeastern boundary of Marion County and the southern boundary of Clackamas County.
Oak Grove Fork Clackamas River is a 21-mile (34 km) tributary of the Clackamas River in the U.S. state of Oregon. From its headwaters in the Warm Springs Indian Reservation near Abbot Pass in the Cascade Range, the river flows generally west through Mount Hood National Forest in Clackamas County to the unincorporated community of Ripplebrook. Here it enters the main stem of the Clackamas River. Oak Grove Fork feeds Timothy Lake and Lake Harriet, two artificial impoundments built along its course to control water flows to hydroelectric plants.
Cougar Dam is a 519-foot (158 m) tall rockfill hydroelectric dam in the U.S. state of Oregon. It has a gated concrete spillway and a powerhouse with two turbines totaling 25 megawatts of electric power.
The North Fork Clackamas River is a tributary, about 11 miles (18 km) long, of the Clackamas River in the U.S. state of Oregon. Originating at nearly 4,000 feet (1,200 m) above sea level on the west side of the Cascade Range, it flows westward through Mount Hood National Forest. It joins the Clackamas at North Fork Reservoir, about 32 miles (51 km) from the larger river's confluence with the Willamette River. From source to mouth, the following tributaries enter the river: Dry Creek from the right bank, Boyer Creek from the left bank, then Whiskey, Bedford, Bee, and Fall creeks, all from the right.
The John C. Boyle Dam is a hydroelectric dam located in southern Oregon, United States. It is on the upper Klamath River, south (downstream) of Keno, and about 12 miles north of the California border. Originally developed and known as Big Bend, the John C. Boyle dam and powerhouse complex was re-dedicated to honor the pioneer hydroelectric engineer who was responsible for the design of virtually all of the Klamath Hydroelectric Project.
Little Butte Creek is a 17-mile-long (27 km) tributary of the Rogue River in the U.S. state of Oregon. Its drainage basin consists of approximately 354 square miles (917 km2) of Jackson County and another 19 square miles (49 km2) of Klamath County. Its two forks, the North Fork and the South Fork, both begin high in the Cascade Range near Mount McLoughlin and Brown Mountain. They both flow generally west until they meet near Lake Creek. The main stem continues west, flowing through the communities of Brownsboro, Eagle Point, and White City, before finally emptying into the Rogue River about 3 miles (5 km) southwest of Eagle Point.
