Oak Grove Fork Clackamas River
Encyclopedia
Oak Grove Fork Clackamas River is a 21 miles (33.8 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.
and falls 2357 feet (718.4 m) between source and mouth to an elevation of 1362 feet (415.1 m). The main stem begins in the Cascade Range near Abbot Pass, a mountain gap at 45°07′50"N 121°42′18"W, on the border between Clackamas County and Wasco County
. Originating on the Warm Springs Indian Reservation, the river flows generally west about 21 miles (33.8 km) through the Mount Hood National Forest to the unincorporated community of Ripplebrook, where it joins the main stem of the Clackamas River.
From its source, the river flows about 2 miles (3.2 km) through a landform
known as Big Meadows before leaving the reservation. Shortly thereafter, it crosses the Pacific Crest Trail
, which follows the river from there to Timothy Lake. Oak Grove Fork then flows between the Clackamas Lake Campground and Clackamas Lake, which lies to the left of the river, before entering Timothy Lake about 17 miles (27.4 km) from the mouth. From here to Ripplebrook, Forest Road 57 follows the river. Campgrounds on the lake shore to the left include Oak Fork, Gone Creek, Hood View, and Pine Point. Meditation Point Campground lies on the opposite shore. While flowing through Timothy Lake, the elevation of which is 3227 feet (983.6 m) above sea level, Oak Grove Fork receives Crater Creek, Cooper Creek, and Dinger Creek, all from the right. The river exits the lake via a spillway
15.8 miles (25.4 km) from the mouth.
Just 0.3 mile (0.482802 km) below the spillway, the river passes the USGS gauge station at Timothy Lake, then receives Anvil Creek from the right, Stone Creek from the left, Buck Creek from the right, Peavine Creek from the left, and Shellrock Creek and Cat Creek, both from the right, before reaching the USGS gauge above Lake Harriet. Lake Harriet Campground lies along the shore to the right. Flowing through the lake, the river receives Kelley Creek from the left, then exits the lake and receives Sam Creek from the left about 6 miles (9.7 km) from the mouth. Then the river receives Skunk Creek and Canyon Creek from the right, Butte Creek from the left, and Station Creek and Pint Creek, both from the right, before passing Ripplebrook, Ripplebrook Campground, the Ripplebrook Ranger Station and Heliport, and the southeastern terminus of Oregon Route 224, which all lie to the right. Shortly thereafter, the river flows by Rainbow Campground, which lies to the left, and enters the Clackamas River about 53 miles (85.3 km) above its confluence with the Willamette River at Gladstone.
monitors the flow of Oak Grove Fork at two stations, one below Timothy Lake, 15.5 miles (24.9 km) from the mouth, and the other above a Portland General Electric
(PGE) power plant intake, 6.7 miles (10.8 km) from the mouth. The average flow of the river at the Timothy Lake gauge is 131 cuft/s. This is from a drainage basin
of 54.4 square miles (140.9 km²). The maximum flow recorded there was 2110 cuft/s on December 24, 1964, and the minimum flow was 3.7 cuft/s on September 23, 1968. At the power plant gauge, the average flow is 511 cuft/s from a drainage basin of 124 square miles (321.2 km²). The maximum flow recorded there was 5000 cuft/s on January 7, 1923, and the minimum flow was 128 cuft/s on August 16, 2004.
Clackamas River
The Clackamas River is an approximately tributary of the Willamette River in northwestern Oregon, in the United States. As it drains an area of about , the Clackamas passes through mostly forested and rugged mountainous terrain in its upper reaches, and passes through agricultural and urban areas...
in the U.S. state of Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
. From its headwaters in the Warm Springs Indian Reservation
Warm Springs Indian Reservation
The Warm Springs Indian Reservation consists of 1,019.385 sq mi in north central Oregon, in the United States, and is occupied and governed by the Confederated Tribes of Warm Springs.-Tribes:...
near Abbot Pass in the Cascade Range
Cascade Range
The Cascade Range is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as the North Cascades, and the notable volcanoes known as the High Cascades...
, the river flows generally west through Mount Hood National Forest
Mount Hood National Forest
The Mount Hood National Forest is located east of the city of Portland, Oregon, and the northern Willamette River valley. The Forest extends south from the Columbia River Gorge across more than of forested mountains, lakes and streams to the Olallie Scenic Area, a high lake basin under the slopes...
in Clackamas County to the unincorporated community of Ripplebrook
Ripplebrook, Oregon
Ripplebrook is an unincorporated community in Clackamas County, Oregon, United States. It is located at the eastern terminus of Oregon Route 224, at an intersection with forest highways 46 and 57, in the Mount Hood National Forest. It is near the confluence of the Clackamas River with the Oak Grove...
. Here it enters the main stem of the Clackamas River. Oak Grove Fork feeds Timothy Lake
Timothy Lake
Timothy Lake is a lake about southeast of Portland, Oregon, United States. It is in close proximity to Clear Lake and an impoundment of the Oak Grove Fork Clackamas River. The compacted-earth dam was built on Timothy Meadows in 1956 to regulate flow to Lake Harriet and the power plant was...
and Lake Harriet
Lake Harriet (Clackamas County, Oregon)
Lake Harriet is a reservoir in Clackamas County of the U.S. state of Oregon.It is an impoundment of the Oak Grove Fork Clackamas River, located southeast of Portland and southwest of Government Camp....
, two artificial impoundments built along its course to control water flows to hydroelectric
Hydroelectricity
Hydroelectricity is the term referring to electricity generated by hydropower; the production of electrical power through the use of the gravitational force of falling or flowing water. It is the most widely used form of renewable energy...
plants.
Course
The Oak Grove Fork Clackamas River arises at an elevation of 3719 feet (1,133.6 m) above sea levelSea level
Mean sea level is a measure of the average height of the ocean's surface ; used as a standard in reckoning land elevation...
and falls 2357 feet (718.4 m) between source and mouth to an elevation of 1362 feet (415.1 m). The main stem begins in the Cascade Range near Abbot Pass, a mountain gap at 45°07′50"N 121°42′18"W, on the border between Clackamas County and Wasco County
Wasco County, Oregon
Wasco County is a county located in the U.S. state of Oregon. The county is named for a local tribe of Native Americans, the Wasco, a Chinook tribe who lived on the south side of the Columbia River. In 2010, its population was 25,213...
. Originating on the Warm Springs Indian Reservation, the river flows generally west about 21 miles (33.8 km) through the Mount Hood National Forest to the unincorporated community of Ripplebrook, where it joins the main stem of the Clackamas River.
From its source, the river flows about 2 miles (3.2 km) through a landform
Landform
A landform or physical feature in the earth sciences and geology sub-fields, comprises a geomorphological unit, and is largely defined by its surface form and location in the landscape, as part of the terrain, and as such, is typically an element of topography...
known as Big Meadows before leaving the reservation. Shortly thereafter, it crosses the Pacific Crest Trail
Pacific Crest Trail
The Pacific Crest Trail is a long-distance mountain hiking and equestrian trail on the Western Seaboard of the United States. The southern terminus is at the California border with Mexico...
, which follows the river from there to Timothy Lake. Oak Grove Fork then flows between the Clackamas Lake Campground and Clackamas Lake, which lies to the left of the river, before entering Timothy Lake about 17 miles (27.4 km) from the mouth. From here to Ripplebrook, Forest Road 57 follows the river. Campgrounds on the lake shore to the left include Oak Fork, Gone Creek, Hood View, and Pine Point. Meditation Point Campground lies on the opposite shore. While flowing through Timothy Lake, the elevation of which is 3227 feet (983.6 m) above sea level, Oak Grove Fork receives Crater Creek, Cooper Creek, and Dinger Creek, all from the right. The river exits the lake via a spillway
Spillway
A spillway is a structure used to provide the controlled release of flows from a dam or levee into a downstream area, typically being the river that was dammed. In the UK they may be known as overflow channels. Spillways release floods so that the water does not overtop and damage or even destroy...
15.8 miles (25.4 km) from the mouth.
Just 0.3 mile (0.482802 km) below the spillway, the river passes the USGS gauge station at Timothy Lake, then receives Anvil Creek from the right, Stone Creek from the left, Buck Creek from the right, Peavine Creek from the left, and Shellrock Creek and Cat Creek, both from the right, before reaching the USGS gauge above Lake Harriet. Lake Harriet Campground lies along the shore to the right. Flowing through the lake, the river receives Kelley Creek from the left, then exits the lake and receives Sam Creek from the left about 6 miles (9.7 km) from the mouth. Then the river receives Skunk Creek and Canyon Creek from the right, Butte Creek from the left, and Station Creek and Pint Creek, both from the right, before passing Ripplebrook, Ripplebrook Campground, the Ripplebrook Ranger Station and Heliport, and the southeastern terminus of Oregon Route 224, which all lie to the right. Shortly thereafter, the river flows by Rainbow Campground, which lies to the left, and enters the Clackamas River about 53 miles (85.3 km) above its confluence with the Willamette River at Gladstone.
Discharge
The United States Geological SurveyUnited States Geological Survey
The United States Geological Survey is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The organization has four major science disciplines, concerning biology,...
monitors the flow of Oak Grove Fork at two stations, one below Timothy Lake, 15.5 miles (24.9 km) from the mouth, and the other above a Portland General Electric
Portland General Electric
Portland General Electric is an electrical utility based in Portland in the U.S. state of Oregon. It distributes electricity to customers in parts of Multnomah, Clackamas, Marion, Yamhill, Washington, and Polk counties - half of the inhabitants of Oregon...
(PGE) power plant intake, 6.7 miles (10.8 km) from the mouth. The average flow of the river at the Timothy Lake gauge is 131 cuft/s. This is from a drainage basin
Drainage basin
A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...
of 54.4 square miles (140.9 km²). The maximum flow recorded there was 2110 cuft/s on December 24, 1964, and the minimum flow was 3.7 cuft/s on September 23, 1968. At the power plant gauge, the average flow is 511 cuft/s from a drainage basin of 124 square miles (321.2 km²). The maximum flow recorded there was 5000 cuft/s on January 7, 1923, and the minimum flow was 128 cuft/s on August 16, 2004.