The Klamath Basin is the region in the U.S. states of Oregon and California drained by the Klamath River. It contains most of Klamath County and parts of Lake and Jackson counties in Oregon, and parts of Del Norte, Humboldt, Modoc, Siskiyou, and Trinity counties in California. The 15,751-square-mile (40,790 km2) drainage basin is 35% in Oregon and 65% in California. In Oregon, the watershed typically lies east of the Cascade Range, while California contains most of the river's segment that passes through the mountains. In the Oregon-far northern California segment of the river, the watershed is semi-desert at lower elevations and dry alpine in the upper elevations. In the western part of the basin, in California, however, the climate is more of temperate rainforest, and the Trinity River watershed consists of a more typical alpine climate.
The Upper Klamath Watershed lies between the Cascade Range and the Basin and Range Province in southern Oregon and northern California. Bedrock stratigraphy in the area includes volcanic deposits, volcanic ejecta, and fluviolacustrine deposits.This creates three general hydrologic layers: 1) Highly permeable basalt with an older depositional age serving as the principle aquifer, 2) fluvial deposits made up of tuff, shale, agglomerate, sandstone, and volcanic ash that are collectively known as the Yonna Formation and act as a groundwater cap, and 3) more recent eruptive volcanic deposits that overlie the aquifer. Little water is able to permeate through the upper volcanic deposit layers to the principle aquifers. Groundwater is able to move freely throughout the upper basin despite geologic structures that occur due to normal faulting which only confine groundwater on a local scale. Artesian wells discharging into the Upper Klamath Lake are essential for recharge into the lake and Klamath River flow throughout the year. Snowmelt is currently a large contributor of groundwater recharge in the Upper Klamath Basin.
The drainage basins of the Williamson and Sprague Rivers, in Oregon, are to the north and northeast of Upper Klamath Lake. Together, the two watersheds cover 3,069 square miles (7,950 km2), or 19.4% of the Klamath River watershed. The basin of the Lost River, the largest subwatershed by area, lies to the southeast of Upper Klamath Lake and to the east of Lower Klamath Lake. This covers 3,009 square miles (7,790 km2) or 19.1% of the Klamath River watershed - nearly as much as the Williamson and Sprague. Proceeding west, the adjoining Butte Creek, Shasta, Scott and Salmon River watersheds have 603 square miles (1,560 km2), 795 square miles (2,060 km2), 813 square miles (2,110 km2), and 750 square miles (1,900 km2), respectively. These account for 4.3%, 5%, 5.2%. and 5% of the Klamath River watershed, respectively, or 19.5% of the watershed if put together.
Further southwest, the watershed of the Trinity River, the second largest subwatershed of the Klamath, has 2,965 square miles (7,680 km2) or 19% of the watershed. The watershed of the South Fork Trinity River is 980 square miles (2,500 km2) - 33% of the Trinity watershed or 6% of the Klamath watershed. The primary tributaries of the Klamath together account for 77% of the total Klamath watershed - the remaining land area is drained by smaller tributaries such as Jenny Creek, Fall Creek and Blue Creek.
Upper Klamath Lake is the largest present-day body of water in the Klamath River watershed, covering 96 square miles (250 km2) on average, with a shoreline of 87 miles (140 km). It is also the largest freshwater lake in the state of Oregon. Historically, Lower Klamath Lake and Tule Lake were one interconnected freshwater marsh that totaled 195 square miles (510 km2) - more than twice the present-day dimensions of Upper Klamath Lake, and larger than Lake Tahoe in central California. This interconnected wetland still supports up to 3.7 million migrating birds per year. In wet years, the two lakes would connect to Upper Klamath Lake, forming one huge body of water. These lakes occupy the basin that was prehistorically occupied by Lake Modoc, a 1,100-square-mile (2,800 km2) freshwater lake that covered the entire Upper Klamath Basin, or 7% of the watershed - an area three times larger than the massive Salton Sea in southern California. This lake existed up to 11,000 years ago at the end of the most recent ice age. Today, Upper Klamath Lake encompasses just 0.6% of the Klamath watershed.
There are also several artificial bodies of water in the watershed - including Lake Ewauna, J.C. Boyle Reservoir, Copco Lake, and Iron Gate Reservoir on the main Klamath. 3.8 square miles (9.8 km2) in size, and is about 20 miles (30 km) long. The J.C. Boyle Reservoir is much smaller, with a surface area of 0.65 square miles (1.7 km2). Copco Reservoir is about 5.4 miles (8.7 km) long and is 1 square mile (2.6 km2) in area. Iron Gate Reservoir covers 1.4 square miles (3.6 km2) and is about 6.8 miles (10.9 km) long. Together, the four lower mainstem reservoirs total just 6.85 square miles (17.7 km2), or 0.04% of the Klamath River watershed.Lake Ewauna, also called Keno Reservoir, is
Trinity Lake, on the mainstem of the Trinity River, is the largest tributary reservoir in the Klamath River watershed. At 25 square miles (65 km2) in size, it is larger than all four mainstem Klamath reservoirs combined (excluding Upper Klamath Lake).
According to the USGS watershed classification system, the Klamath Watershed is a 6-digit, level 3 Accounting Unit within Region 18, known as the California watershed region.The accounting unit of the Klamath Watershed is 180102 and includes twelve 8-digit Hydrologic Units (HUCs) covering 9.4 million acres. In the 2000 census, about 114,000 people were estimated to be living within the Klamath Watershed. The largest population centers include Klamath Falls, Oregon (19,462) and Yreka, California (7,290). Land ownership within the basin breaks down into the following: about 90,000 acres are controlled by tribal reservations, 6.2 million acres are managed by public agencies (including the Bureau of Land Management, National Forests, National Wildlife Refuges, and National Park Service), and 3.7 million is privately owned. Of the privately owned land, 557,000 acres are used for farming 80% of which is irrigated farmland. Nearly half of irrigated land utilizes water from the Bureau of Land Management’s Klamath Project. The vast majority of privately owned agriculture and rangeland occurs in the Lost River and Shasta River sub-basins.
The Klamath Basin watershed includes:
These three rivers are located above (north) of the Klamath Lake basin:
These features are inside or near the Klamath Lake basin:
These are the major downstream tributaries of the Klamath River:
Communities in the Klamath Basin include:
The Sacramento River is the principal river of Northern California in the United States and is the largest river in California. Rising in the Klamath Mountains, the river flows south for 400 miles (640 km) before reaching the Sacramento–San Joaquin River Delta and San Francisco Bay. The river drains about 26,500 square miles (69,000 km2) in 19 California counties, mostly within the fertile agricultural region bounded by the Coast Ranges and Sierra Nevada known as the Sacramento Valley, but also extending as far as the volcanic plateaus of Northeastern California. Historically, its watershed has reached as far north as south-central Oregon where the now, primarily, endorheic (closed) Goose Lake rarely experiences southerly outflow into the Pit River, the most northerly tributary of the Sacramento.
Ahjumawi Lava Springs State Park is a state park of California in the United States. It is located in remote northeastern Shasta County and is only accessible to the public by boat.
The Klamath River flows 257 miles (414 km) through Oregon and northern California in the United States, emptying into the Pacific Ocean. By average discharge, the Klamath is the second largest river in California after the Sacramento River. It drains an extensive watershed of almost 16,000 square miles (41,000 km2) that stretches from the arid country of south-central Oregon to the temperate rainforest of the Pacific coast. Unlike most rivers, the Klamath begins in the high desert and flows toward the mountains – carving its way through the rugged Cascade Range and Klamath Mountains before reaching the sea. The upper basin, today used for farming and ranching, once contained vast freshwater marshes that provided habitat for abundant wildlife, including millions of migratory birds. Most of the lower basin remains wild, with much of it designated wilderness. The watershed is known for this peculiar geography, and the Klamath has been called "a river upside down" by National Geographic magazine.
The Pit River is a major river draining from northeastern California into the state's Central Valley. The Pit, the Klamath and the Columbia are the only three rivers in the U.S. that cross the Cascade Range.
The McCloud River is a 77.1-mile (124.1 km) long river that flows east of and parallel to the upper Sacramento River, in Siskiyou County and Shasta County in northern California in the United States. Protected under California's Wild and Scenic Rivers Act (1972), it drains a scenic mountainous area of the Cascade Range, including part of Mount Shasta. It is a tributary of the Pit River, which in turn flows into the Sacramento River. The three rivers join in Shasta Lake, formed by Shasta Dam north of Redding.
The Shasta River is a tributary of the Klamath River, approximately 58 miles (93 km) long, in northern California in the United States. It drains the Shasta Valley on the west and north sides of Mount Shasta in the Cascade Range.
The Trinity River is a major river in northwestern California in the United States, and is the principal tributary of the Klamath River. The Trinity flows for 165 miles (266 km) through the Klamath Mountains and Coast Ranges, with a watershed area of nearly 3,000 square miles (7,800 km2) in Trinity and Humboldt Counties. Designated a National Wild and Scenic River, along most of its course the Trinity flows swiftly through tight canyons and mountain meadows.
The Williamson River of south-central Oregon in the United States is about 100 miles (160 km) long. It drains about 3,000 square miles (7,800 km2) east of the Cascade Range. Together with its principal tributary, the Sprague River, it provides over half the inflow to Upper Klamath Lake, the largest freshwater lake in Oregon. The lake's outlet is the Link River, which flows into Lake Ewauna and the Klamath River.
The Shasta–Trinity National Forests are federally designated forests in northern California, United States. Combined, they are the largest National Forest in California and are managed by the U.S. Forest Service. The 2,210,485 acre combined-forest encompasses five wilderness areas, hundreds of mountain lakes and 6,278 miles (10,103 km) of streams and rivers. Major features include Shasta Lake, the largest man-made lake in California and Mount Shasta, elevation 14,179 feet (4,322 m).
The Link River is a short river connecting Upper Klamath Lake to Lake Ewauna in the city of Klamath Falls in the U.S. state of Oregon. Draining a basin of 3,810 square miles (9,900 km2), the river begins at the southern end of Klamath Lake and flows a short distance to the Link River Dam and continues 1.5 miles (2.4 km) to the head of Lake Ewauna. The "falls" from which Klamath Falls derives its name, and which in reality are best described as rapids rather than falls, are visible a short distance below the dam, though the water flow is generally insufficient to provide water flow over the rocks. The Klamath River begins at the narrow southern end of Lake Ewauna and flows 253 miles (407 km) from there to the Pacific Ocean.
The Klamath Project is a water-management project developed by the United States Bureau of Reclamation to supply farmers with irrigation water and farmland in the Klamath Basin. The project also supplies water to the Tule Lake National Wildlife Refuge, and the Lower Klamath National Wildlife Refuge. The project was one of the first to be developed by the Reclamation Service, which later became the Bureau of Reclamation.
The Cascades ecoregion is a Level III ecoregion designated by the United States Environmental Protection Agency (EPA) in the U.S. states of Washington, Oregon, and California. Somewhat smaller than the Cascade mountain range for which it is named, the ecoregion extends north to Snoqualmie Pass, near Seattle, and south to Hayden Pass, near the Oregon-California border, including the peaks and western slopes of most of the High Cascades. A discontiguous section is located on Mount Shasta in California.
The Eastern Cascades Slopes and Foothills ecoregion is a Level III ecoregion designated by the United States Environmental Protection Agency (EPA) in the U.S. states of Oregon, Washington, and California. In the rain shadow of the Cascade Range, the eastern side of the mountains experiences greater temperature extremes and receives less precipitation than the west side. Open forests of ponderosa pine and some lodgepole pine distinguish this region from the Cascades ecoregion, where hemlock and fir forests are more common, and from the lower, drier ecoregions to the east, where shrubs and grasslands are predominant. The vegetation is adapted to the prevailing dry, continental climate and frequent wildfire. Volcanic cones and buttes are common in much of the region.
The South Fork Trinity River is the main tributary of the Trinity River, in the northern part of the U.S. state of California. It is part of the Klamath River drainage basin. It flows generally northwest from its source in the Klamath Mountains, 92 miles (148 km) through Humboldt and Trinity Counties, to join the Trinity near Salyer. The main tributaries are Hayfork Creek and the East Branch South Fork Trinity River. The river has no major dams or diversions, and is designated Wild and Scenic for its entire length.
The Klamath Diversion was a federal water project proposed by the U.S. Bureau of Reclamation in the 1950s. It would have diverted the Klamath River in Northern California to the more arid central and southern parts of that state. It would relieve irrigation water demand and groundwater overdraft in the Central Valley and boost the water supply for Southern California. Through the latter it would allow for other Southwestern states—Arizona, Nevada, New Mexico and Utah—as well as Mexico to receive an increased share of the waters of the Colorado River.
The Klamath River is a river in southern Oregon and northern California in the United States. This article describes its course.
Hayfork Creek is a tributary of the South Fork Trinity River in Northern California in the United States. At over 50 miles (80 km) long, it is the river's longest tributary and is one of the southernmost streams in the Klamath Basin. It winds through a generally steep and narrow course north then west through the forested Klamath Mountains, but also passes through the Hayfork and Hyampom Valleys, which are the primary agricultural regions of Trinity County.
Cottonwood Creek is a major stream and tributary of the Sacramento River in Northern California. About 68 miles (109 km) long measured to its uppermost tributaries, the creek drains a large rural area bounded by the crest of the Coast Ranges, traversing the northwestern Sacramento Valley before emptying into the Sacramento River near the town of Cottonwood. For its entire length, it defines the boundary of Shasta and Tehama counties. Because Cottonwood Creek is the largest undammed tributary of the Sacramento River, it is known for its Chinook salmon and steelhead runs.
The Klamath River Hydroelectric Project is a series of hydroelectric dams and other facilities on the mainstem of the Klamath River, in a watershed on both sides of the California/Oregon border.
The Klamath river begins below Upper Klamath Lake in Southern Oregon and flows about 300 miles through Northern California until draining into the Pacific ocean. Upper Klamath Lake is the largest freshwater lake in Oregon and was established by the late Pliocene period. The lake fills a graben that is thousands of meters deep. The Klamath Basin lies on the edge of the Basin and Range province and is adjacent to the High Cascades of Southern Oregon.