A Fortress For Forests. As any hiker soon discovers, the Klamath-Siskiyou is not an easy, gentle, or welcoming wilderness. From its chill, dripping coastal rainforest to its knife-edged mountain ridges, sun-baked flats, and tangles of buckbrush and poison oak, the region hardly seems like a sanctuary from the harsh realities of a changeable world. And yet that is exactly what it is: for millions of years, this difficult land has been the last refuge for an amazing array of unique trees and other plants.

For all its great antiquity, the Klamath-Siskiyou has never been subjected massive volcanism and glaciation, the sorts of cataclysms that rework entire regions. Instead, its mountains and valleys have unfailingly offered a complex mosaic of habitats, allowing species with diverse environmental requirements to survive as changing climates eliminated populations elsewhere. It is hard to imagine two more different conifers than the towering redwoods of the fog-bound coast and the stunted foxtail pines of the wind-scoured peaks, but both of these very localized species find what they need to survive on special sites in our region.

The Klamath-Siskiyou has the highest diversity of conifer species in the world, with 30 species overall and an amazing 17 species within one square mile in the Russian Wilderness. This richness reflects the region’s sanctuary role. Many of the conifers, as well as other plant species, reach their range limits here. For example, the region is home to the northernmost Coast Redwoods, the southernmost Alaska yellow cedar, and the westernmost Western Juniper. These species have responded to changing conditions by withdrawing their principal range to more hospitable climes, leaving behind remnant populations in protected pockets of our mountains. Other plants, notably Brewer’s Spruce and the magnificent Port Orford Cedar, are relict species. They survive only in the Klamath-Siskiyou today, but millions of years ago were much more widespread, as revealed by their scattered fossils. This long ebb and flow has filled the Klamath-Siskiyou with the rich pool of life that we recognize today as one of the world’s treasure-troves of biodiversity.

Wildlife Wilderness. The biological wealth of our region is not limited to plants, of course. The case can be illustrated with birds. The Klamath-Siskiyou is host to 392 bird species, 189 of which are confirmed to breed here. This great diversity is possible because of the variety of habitats and plant communities in the region. Birds of the oak woodland and chaparral communities, like the California Towhee and Plain Titmouse, reach their northern limits here, while species of deep coniferous forest, such as the Blue Grouse and the Gray Jay, extend no further south along the Pacific coast.