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The Klamath-Siskiyou Region

The Klamath-Siskiyou ecoregion of southwestern Oregon and northwestern California is a world renowned hub of biological diversity. The mountain ranges and river valleys that define this region are some of the most spectacular in America.

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Craggy Peak and the headwaters of Sucker Creek are found in the nearly 100,000-acre Kangaroo Roadless Area that surround the Red Buttes Wilderness on the Oregon-California border. Photo by Barbara Ullian

Straddling the Oregon-California border, the Klamath-Siskiyou (KS) contains the largest concentration of intact watersheds and roadless wildlands left on the Pacific coast of the U.S.

Click here to view a map of the region. 

Covering nearly 10 million acres, the KS stretches from the Umpqua in the north to California's wine country in the south, from the Pacific Ocean in the west to the mighty Cascade Mountains in the east. Ranging in elevation from sea level to its highest peak, Mt Ashland, at 7,533 feet, the area is rugged and beautiful. More than half of the region is public land.

Complex Natural History

Amongst a tangle of sharp-edged mountains and salmon-strewn rivers, geologists often refer to the ancient KS mountains as, "The Klamath Knot." For all its great antiquity, the KS has never been subject to volcanism and glaciation like the neighboring Cascade and Sierra Mountains. Rather the KS is a result of rocks under heat and pressure folding through time. To illustrate, the Kalmiopsis leachiana is a flower that once grew on an island in the Pacific ocean, and can now be found growing on top of mountains in southwest Oregon. Added to the mix is the fact the region largely remained unglaciated during the last Ice Age when most of the continent was under ice, therefore acting a refuge for plants and animals. Additionally, the area is the confluence of various habitat types, sharing species from the Great Basin, Cascades, Coastal Range, California's Central Valley and the Sierra Nevada. The region's history with fire has also contributed to a rich landscape that changes at most every turn. The KS mountains and valleys offer a complex mosaic of habitats, allowing diverse species to mingle and create unique communities. On the eastside of the region one can find ancient, gnarled western juniper trees, whereas on the westside one can find soggy coastal redwood rainforests.


Clear Waters 
Clear Creek flows into the Klamath River on the southside of the Siskiyou Crest

The region is largely defined by the mighty Rogue watershed in the north and the famous Klamath watershed in the south. These two epic rivers are separated by the rugged Siskiyou Crest Mountain Range that traverses the stateline. These river systems support wild populations of salmon and steelhead and are refugia for salmon populations in the lower 48. These rivers, and their famous tributaries such as the Illinois and Salmon Rivers, attract people from around the world to enjoy the whitewater, fisheries and gorgeous scenery.


The region has a very diverse mosaic landscape, including mixed evergreen and subalpine forests, serpentine vegetation, redwood forest, oak woodlands, savannahs and meadows. The KS supports 36 different species of conifers, more than any other temperate forest in the world. Endemic conifers include the Port-Orford cedar and Brewer's or Weeping spruce. Many conifers live here at the edge of their range, such as Englemann spruce and Alaska yellow cedar. The reigon is also well-known for its vast array of unusual and endemic flowering plants (endemic means that a species exists in this one location and nowhere else on the planet). An estimated 3,500 vascular plant species can be found here, 280 of which are endemic. Rare plants include the Cobra lily, Mt. Ashland lupine, Henderson's horkelia, lavendar paintbrush, Yreka phlox and Gentner's fritillaria.



The forests are home to abundant wildlife - deer, elk, black bears, mountain lions, spotted owls, and rare amphibians such as the Siskiyou Mountain and Scott Bar salamanders. Many species are dependent on uncut forest, abundant road free wildlands and healthy watersheds for their survival, such as the Pacific fisher and wolverine.  Several species have been extirpated from the region, including the grey wolf, grizzly bear, lynx and pronghorn.

The Siskiyou Crest looking west from the McDonald Peak Roadless Area.

Much of the area is protected only by its remoteness and rugged terrain. The Yolla Bolly, Marble Mountain, Trinity Alps, Russian, Siskiyou, Red Butte and Kalmiopsis are protected Wilderness Areas (although some mining and cattle grazing is permitted). High quality habitat connecting these core areas are under ongoing threats from logging, mining, road-building, invasive weeds and cattle grazing. These core areas, and the roadless and old-growth habitat between them, create the largest complex of wildlands on the West Coast of America.


Global Recognition

The Klamath-Siskiyou ecoregion is considered a global center of biodiversity (Wallace 1982), an IUCN Area of Global Botanical Significance (1 of 7 in North America), and is proposed as a World Heritage Site and UNESCO Biosphere Reserve (Vance-Borland et al. 1995).


Fire Suppression

Natural fire cycles were key contributors to the diversity of the Klamath Siskiyou area for millennia. Returning every 10-150 years, fires recycle nutrients, maintain diversity, renew fire-dependent species and leave burned out trees critical for wildlife.

Habitat Loss

Despite incredible biological richness, past clear-cutting has seriously reduced old-growth habitat. Ongoing old-growth logging continues to compromise habitat and connectivity for old-growth dependent species.


Federal Management
Forests in the Red Cap watershed, a tributary of the Klamath River

KS Wild monitors approximately 5 million acres of public land that compose the Rogue and Klamath River watersheds, which are separated by the Siskiyou Crest and South Cascade mountain ranges. These public lands are the Rogue River/Siskiyou, Klamath and Six Rivers National Forests and the Medford and Klamath Districts of the Bureau of Land Management (BLM).  Click here to see a map of federal management in the region.

KS Wild is working to permanently protect the remaining roadless and high quality habitat in the region while encouraging a shift in public lands management from unsustainable logging to restoration efforts and small diameter thinning.