|Location||Clackamas County, Oregon, United States|
|Basin countries||United States|
|Surface area||2.17 square miles (5.6 km2)|
|Average depth||45 feet (14 m)|
|Max. depth||80 feet (24 m)|
|Surface elevation||3,227 feet (984 m)|
Timothy Lake is a lake about 50 miles (80 km) southeast of Portland, Oregon, United States. It is in proximity to Clear Lake and an impoundment of the Oak Grove Fork Clackamas River.
The compacted-earth Timothy Lake Dam was built by Portland General Electric in 1956 to regulate seasonal water flow to Lake Harriet downstream.The dam, 110 feet high and impounding 81,000 acre-feet, does not generate any hydroelectric power itself. In the summer, the lake is a very popular destination for camping, boating, hiking, horseback riding, and mountain biking.
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.
Clackamas County is one of the 36 counties in the U.S. state of Oregon. As of the 2020 census, the population was 421,401, making it Oregon's third-most populous county. Its county seat is Oregon City. The county was named after the Native Americans living in the area, the Clackamas people, who are part of the Chinookan peoples.
Portland General Electric (PGE) is a Fortune 1000 public utility based in Portland, Oregon. It distributes electricity to customers in parts of Multnomah, Clackamas, Marion, Yamhill, Washington, and Polk counties - 44% of the inhabitants of Oregon. Founded in 1888 as the Willamette Falls Electric Company, the company has been an independent company for most of its existence, though was briefly owned by the Houston-based Enron Corporation from 1997 until 2006 when Enron divested itself of PGE during its bankruptcy.
The Sandy River is a 56-mile (90 km) tributary of the Columbia River in northwestern Oregon in the United States. The Sandy joins the Columbia about 14 miles (23 km) upstream of Portland.
The Clackamas River is an approximately 83-mile (134 km) tributary of the Willamette River in northwestern Oregon, in the United States. Draining an area of about 940 square miles (2,435 km2), the Clackamas flows through mostly forested and rugged mountainous terrain in its upper reaches, and passes agricultural and urban areas in its lower third. The river rises in eastern Marion County, about 55 miles (89 km) east-southeast of Salem. The headwaters are on the slopes of Olallie Butte in the Mount Hood National Forest, about 10 miles (16 km) north of Mount Jefferson, at an elevation of 4,909 feet (1,496 m) in the Cascade Range. The Clackamas flows briefly north and then flows northwest through the mountains, passing through North Fork Reservoir and Estacada. It then emerges from the mountains southeast of Portland. It joins the Willamette near Oregon City and forms the boundary between Oregon City and Gladstone.
Lolo Pass is a mountain pass 6 miles (10 km) northwest of Mount Hood and 10 miles (16 km) northeast of Zigzag, Oregon, on the Clackamas–Hood River county line. It divides the Sandy River watershed on the southwest from the Hood River watershed on the northeast.
The Mount Hood National Forest is a U.S. National Forest in the U.S. state of Oregon, located 62 miles (100 km) east of the city of Portland and the northern Willamette River valley. The Forest extends south from the Columbia River Gorge across more than 60 miles (97 km) of forested mountains, lakes and streams to the Olallie Scenic Area, a high lake basin under the slopes of Mount Jefferson. The Forest includes and is named after Mount Hood, a stratovolcano and the highest mountain in the state.
The Bull Run Hydroelectric Project was a Portland General Electric (PGE) development in the Sandy River basin in the U.S. state of Oregon. Originally built between 1908 and 1912 near the town of Bull Run, it supplied hydroelectric power for the Portland area for nearly a century, until it was removed in 2007 and 2008. The project used a system of canals, tunnels, wood box flumes and diversion dams to feed a remote storage reservoir and powerhouse. The entire project was removed because of rising environmental costs. Marmot Dam on the Sandy River was demolished in 2007, and the Little Sandy Dam on the Little Sandy River was taken down in 2008.
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.
The Cove Palisades State Park is a state park in eastern Jefferson County, Oregon, near Culver and Madras in the central part of the state, and is administered by the Oregon Parks and Recreation Department. It is located on the waters and surrounding lands of Lake Billy Chinook, an impoundment of the Crooked, Deschutes, and Metolius rivers.
The Oak Grove Hydroelectric Project is a 44 megawatt hydroelectric plant operated by Portland General Electric (PGE) on the Oak Grove Fork Clackamas River. Water for this project is held by three lakes, built between 1923 and 1956. The dam creates the impoundment Lake Harriet.
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.
Bull Run Lake is a reservoir, an impoundment of the Bull Run River in the U.S. state of Oregon. Providing part of the primary drinking water supply for Portland, Oregon, it rates highly as an oligotrophic lake, a very clean source of water. As of 1925, noted geographer Lewis A. McArthur described the lake as one of the two most important in the state, supplying the drinking water for a third of the state's population.
River Mill Hydroelectric Project, also known as River Mill Dam and Station M, is a hydroelectric dam and powerhouse in Clackamas County, Oregon, United States. It is just north of Estacada, Oregon, on the Clackamas River at river mile 23.5. It received its name from being near a sawmill that was located along the river.
Fish Lake is a reservoir located 4,639 feet (1,414 m) above sea level in Jackson County, Oregon, United States. It is 35 miles (56 km) northeast of Medford. Originally a natural lake, it was enlarged by the 50-foot (15 m) tall Fish Lake Dam, which impounds the north fork of Little Butte Creek, in the Rogue River watershed.
The Little Sandy River is a tributary, roughly 15 miles (24 km) long, of the Bull Run River in the U.S. state of Oregon. Forming west of Mount Hood in the Mount Hood National Forest, it flows generally west, roughly parallel to the Sandy River to the south. Its entire course lies in Clackamas County, and most of its main stem and tributaries are within the Bull Run Watershed Management Unit (BRWMU), a restricted zone that protects Portland's main water supply.
The South Fork Clackamas River is a tributary, roughly 8 miles (13 km) long, of the Clackamas River in the U.S. state of Oregon. Beginning near South Fork Mountain in the western Cascade Range, the river flows generally north through Clackamas County to meet the larger river at Big Cliff. Most of the South Fork's drainage basin lies within the Mount Hood National Forest.
Pelton Dam is a major dam on the Deschutes River in Jefferson County, Oregon, owned and operated as a hydroelectric facility by Portland General Electric, one element of its Pelton Round Butte Project on the Deschutes.
North Fork Reservoir is a reservoir behind North Fork Dam, on the Clackamas River, upriver from Estacada. It is found at an elevation of 666 feet (203 m).