Klamath Mountains 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. Physiographically, the Klamath Mountains include the Siskiyou Mountains, the Marble Mountains, the Scott Mountains, the Trinity Mountains, the Trinity Alps, the Salmon Mountains, and the northern Yolla-Bolly Mountains. They are a section of the larger Pacific Border province, which in turn is part of the Pacific Mountain System (Pacific Coast Ranges) physiographic division. These are the ten highest
Ecology of the Rocky Mountains beetles have begun to impact more old-growth spruce trees in these forests. On exposed, dry slopes at high elevations, subalpine white pine forests replace spruce-fir forests. Common species of the white pine forests include whitebark pine in the northern Rocky Mountains, limber pine in the central and north-central Rocky Mountains, and bristlecone pine in the southern Rocky Mountains. Typical intervals between fires range from 50 to 300 years. The white pines are tolerant of extreme environmental conditions and can be important postfire successional species. The whitebark pine is a keystone species in upper subalpine forests of the northern Rocky Mountains.