The Klamath Mountains are a rugged and lightly-populated mountain range in northwestern California and southwestern Oregon in the western United States. As a mountain system within both the greater Pacific Coast Ranges and the California Coast Ranges, the Klamath Mountains have a varied geology, with substantial areas of serpentinite and marble, and a climate characterized by moderately cold winters with very heavy snowfall and warm, very dry summers with limited rainfall, especially in the south. As a consequence of the geology and soil types, the mountains harbor several endemic or near-endemic trees, forming one of the largest collections of conifers in the world. The mountains are also home to a diverse array of fish and animal species, including black bears, large cats, owls, eagles, and several species of Pacific salmon. Millions of acres in the mountains are managed by the United States Forest Service. The northernmost and largest sub-range of the Klamath Mountains are the Siskiyou Mountains.
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. Its nearly 16,000-square-mile (41,000 km2) watershed stretches from the high desert of south-central Oregon to the temperate rainforest of the North Coast. Unlike most rivers, the Klamath begins in a desert region and flows through the rugged Cascade Range and Klamath Mountains before reaching the ocean; National Geographic magazine has called the Klamath "a river upside down".
The Siskiyou Mountains are a coastal subrange of the Klamath Mountains, and located in northwestern California and southwestern Oregon in the United States. They extend in an arc for approximately 100 miles (160 km) from east of Crescent City, California, northeast along the north side of the Klamath River into Josephine and Jackson counties in Oregon. The mountain range forms a barrier between the watersheds of the Klamath River to the south and the Rogue River to the north. Accordingly, much of the range is within the Rogue River – Siskiyou and Klamath national forests, and the Pacific Crest Trail follows a portion of the crest of the Siskiyous.
The Trinity Alps are a mountain range in Trinity County and Siskiyou County in Northern California. They are a subrange of the Klamath Mountains located to the north of Weaverville.
The Shasta–Trinity National Forest is a federally designated forest in northern California, United States. It is the largest National Forest in California and is managed by the U.S. Forest Service. The 2,210,485 acre 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).
Klamath National Forest is a 1,737,774-acre national forest, in the Klamath Mountains and Cascade Range, located in Siskiyou County in northern California, but with a tiny extension into southern Jackson County in Oregon. The forest contains continuous stands of ponderosa pine, Jeffrey pine, Douglas fir, red fir, white fir, lodgepole pine, Baker Cypress, and incense cedar. Old growth forest is estimated to cover some 168,000 acres (680 km2) of the forest land. Forest headquarters are located in Yreka, California. There are local ranger district offices located in Fort Jones, Happy Camp, and Macdoel, all in California. The Klamath was established on May 6, 1905. This forest includes the Kangaroo Lake and the Sawyers Bar Catholic Church is located within the boundaries of the Forest. The Forest is managed jointly with the Butte Valley National Grassland.
The Six Rivers National Forest is a U.S. National Forest located in the northwestern corner of California. It was established on June 3rd, 1947 by U.S. President Harry S. Truman from portions of Klamath, Siskiyou and Trinity National Forests. Its over one million acres (4,000 km2) of land contain a variety of ecosystems and 137,000 acres (550 km2) of old growth forest. It lies in parts of four counties; in descending order of forestland area they are Del Norte, Humboldt, Trinity, and Siskiyou counties. The forest is named after the Eel, Van Duzen, Klamath, Trinity, Mad, and Smith rivers, which pass through or near the forest's boundaries.
The King Range is a mountain range of the Outer Northern California Coast Ranges System, located entirely within Humboldt County on the North Coast of California.
The Trinity Mountains are a subrange of the Klamath Mountains, one of the ranges within the California Coast Ranges and part the greater Pacific Coast Ranges, the coastal mountain system extending from Mexico to Alaska. The Trinity Mountains subrange rises in Siskiyou County and eastern Trinity County, Northern California.
The Coast Ranges of California span 400 miles (644 km) from Del Norte or Humboldt County, California, south to Santa Barbara County. The other three coastal California mountain ranges are the Transverse Ranges, Peninsular Ranges and the Klamath Mountains.
The Salmon River is a 19.6-mile-long (31.5 km) tributary to the Klamath River in western Siskiyou County, California.
The Rogue River–Siskiyou National Forest is a United States National Forest in the U.S. states of Oregon and California. The formerly separate Rogue River and Siskiyou National Forests were administratively combined in 2004. Now, the Rogue River–Siskiyou National Forest ranges from the crest of the Cascade Range west into the Siskiyou Mountains, covering almost 1.8 million acres (7,300 km2). Forest headquarters are located in Medford, Oregon.
The Coast Range ecoregion is a Level III ecoregion designated by the Environmental Protection Agency (EPA) in the U.S. states of Washington, Oregon, and California. It stretches along the Pacific Coast from the tip of the Olympic Peninsula in the north to the San Francisco Bay in the south, including Grays Harbor, Willapa Bay, and the Long Beach Peninsula in Washington, the entire length of the Oregon Coast, and the Northern California Coast. Named for the Coast Range mountains, it encompasses the lower elevations of the Olympic Mountains, the Oregon Coast Range, the Californian North Coast Ranges, and surrounding lowlands.
The Klamath Mountains ecoregion of Oregon and California lies inland and north of the Coast Range ecoregion, extending from the Umpqua River in the north to the Sacramento Valley in the south. It encompasses the highly dissected ridges, foothills, and valleys of the Klamath and Siskiyou Mountains. It corresponds to the Level III ecoregion designated by the Environmental Protection Agency and to the Klamath-Siskiyou forests ecoregion designated by the World Wide Fund for Nature.
The Yolla Bolly–Middle Eel Wilderness is a federally designated wilderness area in the Yolla Bolly Range of the southern Klamath Mountains and the Inner Northern California Coast Ranges, in Northern California.
The Castle Crags Wilderness is a 12,232-acre (49.50 km2) wilderness area in the Castle Crags rock formations of the Trinity Mountains, and within the Shasta-Trinity National Forest, in northwestern California. It is located in Siskiyou County and Shasta County, 40 miles (64 km) north of Redding and south of Mount Shasta City.
The Scott Mountains are a subrange of the Klamath Mountains located in Siskiyou County, in northwestern California. A high point is Scott Mountain Summit, a mountain gap-pass at 5,554 feet (1,693 m) in elevation.
The Marble Mountain Wilderness is a 241,744-acre (978.30 km2) wilderness area located 60 miles (97 km) southwest of Yreka, California, in the United States. It is managed by the United States Forest Service and is within the Klamath National Forest in Siskiyou County. The land was first set aside in April 1931 as the Marble Mountain Primitive Area, which comprised 234,957 acres (950.84 km2). It was one of four areas to gain primitive status under the Forest Service's L-20 regulations that year. In 1964, it became a federally designated wilderness area when the U.S. Congress passed the Wilderness Act.
The Russian Wilderness is a wilderness area of 12,000 acres (49 km2) located approximately 65 miles (105 km) northeast of Eureka in northern California. It is within the Klamath National Forest in Siskiyou County and is managed by the US Forest Service. It was added to the National Wilderness Preservation System when the US Congress passed the California Wilderness Act of 1984.
Blue Creek is a 23-mile (37 km) long stream in the Northern Coast Ranges of California, and is the lowermost major tributary of the Klamath River. The creek begins in Elk Valley, in the Siskiyou Wilderness of the Six Rivers National Forest in Del Norte County. It flows southwest, receiving several major tributaries including the East Fork, Crescent City Fork, Nickowitz Creek, Slide Creek and the West Fork. It flows into the Klamath River in Humboldt County, 16 miles (26 km) upstream from where the Klamath empties into the Pacific Ocean.
