WCS North America

Klamath River Watershed

Spanning more than 12 million acres, an area the size of the states of Vermont and New Hampshire, the Klamath-Siskiyou eco-region of southwestern Oregon and northwestern California is a world-renowned hub of biological diversity, recognized as an IUCN Area of Global Botanical Significance (one of seven in North America), and proposed as a World Heritage Site and UNESCO Biosphere Reserve. This region harbors one of the richest temperate coniferous forests in the world. The high species diversity in the Klamath-Siskiyou region is explained, in large part, by the fact that this area remained ice-free during the last Pleistocene glacier advance, acting as a refugium for many plant and animal species unable to survive elsewhere. Additionally, the area is at the confluence of various habitat types, sharing species from the Great Basin, Cascade Mountains, Coastal Mountain Ranges, California's Central Valley and the Sierra Nevada Mountains. The region’s mountains and valleys offer a complex mosaic of habitats along an elevation gradient, allowing for distinct communities including temperate rain forests, moist inland forests, oak forests and savannas, high elevation forests, and alpine grasslands.

The cultural history of the Klamath-Siskiyou region is as rich as its natural history. The region supported and continues to be home to many Native Americans, including the Karok, Yurok, and Hoopa Tribes along the Klamath and Trinity Rivers, and the Latgawa, Takelma, Shasta and different subtribes of the Coquille along the Rogue River. Today the region supports a native and non-native population of approximately 853,000, a majority living in a handful of small, but growing in many cases, cities and towns along the I-5 interstate highway corridor and along the coast. In many cases, these communities are supported by extensive agriculture and grazing in the valley bottoms and logging and mining in the mountainous forests of the region.

In 2004, the Wildlife Conservation Society began working in the Klamath-Siskiyou in collaboration with the Hoopa Valley Tribe and other federal, state, and private partners to develop region-wide forest management recommendations for the imperiled Pacific fisher. Our conservation approach in the Klamath-Siskiyou involves developing collaborative, field-science based solutions to reduce the impacts of a diverse group of extractive and agricultural industries that support a significant portion of the livelihoods in the region.

Conservation Challenges

Much of Klamath-Siskiyou region is protected as federally-designated Wilderness Areas, including the Trinity Alps, Russian, Yolla Bolly, Marble Mountain, Siskiyou, Red Butte and Kalmiopsis Wilderness Areas. However, high quality habitats connecting these core areas, often in lower elevation river valleys, are threatened by logging, severe wildfires, road-building, agricultural demands on water resources, mining, invasive weeds, and cattle grazing.


In the Pacific northwest, nearly 90% of mature forests over 150 years of age have been logged. In conjunction with the thousands of miles of logging roads now traversing federal and private forests, logging has significantly degraded and fragmented a majority of the Klamath-Siskiyou region. The effects of logging have impacted forest and aquatic species alike, ranging from imperiled Pacific fishers, threatened spotted owls, threatened foothill yellow-legged frogs, and endangered northern California coho salmon. WCS is working with the Hoopa Valley Tribe and other regional partners to collect information on the habitat use patterns of fishers and develop forest management recommendations to inform regional foresters on methods to improve sustainable forestry practices.

Wildfire and climate change
Human influences have altered the fire environment of the Klamath Siskiyou region. Logging has converted historically multi-aged, closed forests to single-aged, open forests which are more susceptible to larger and more severe wildfires. These impacts are also occurring under the influence of climate change. It is suspected that a warming climate will likely result in extended fire seasons and increases in total area burned throughout the Klamath-Siskiyou region. While fuels management projects strive to reduce the risk of severe wildfires and sustain the forested habitats imperiled fishers depend on, they may impose their own set of threats to individual fishers and fisher populations. WCS is working to quantify the short-term impacts of fuels and other forest management projects on fisher habitat use and predation risk. This information will be used to better direct these types of projects while conserving fisher habitat.

Conservation Approach

WCS is co-directing and collaborating with various partners in northern California, including the Hoopa Valley Tribe, to conserve remnant fisher populations by collecting information on fisher dens, habitat requirements, and forest thinning/forest fire fuels management projects to inform federal, state, and tribal conservation strategies. Through these efforts we work with stakeholders to develop and adopt forest- and fuels-management practices that minimize impacts to wildlife.


Pacific Fisher within Hoopa Tribal Lands

Conservation challenges for wildlife ultimately affect landscapes and people.  In the unique case of WCS's work with the Hoopa Tribe to conserve Pacific fisher is a perfect example of how our organization assists Native American communities to develop field-science-based solutions to direct natural resource management and wildlife conservation decision-making. Read More >>

Latest Publications

All Klamath River Watershed Publications >>

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WCS North America Program
301 North Willson Avenue Bozeman, MT, 59715 USA
(406) 522-9333

Key Staff

Sean Matthews
Hoopa Fisher Landscape Coordinator
All Klamath River Watershed Staff >>