The South Warner Wilderness is a federally designated wilderness area east of Alturas, California, USA. It encompasses more than of the Warner Mountains. It is within the Modoc National Forest and managed by the US Forest Service. Elevations range from to 9,895 feet at Eagle Peak. The highest parts of the Warner Mountains were set aside in 1931 as a primitive area. In 1964, the Wilderness Act created the South Warner Wilderness. In 1984, were added to the wilderness with the passage of the California Wilderness Act. The Warner crest divides waters that flow west into the Sacramento/Pit River drainage, and east into the Great Basin Alkali lakes of Surprise Valley. Much of the crest is a narrow ridgeline with notable peaks such as Emerson Peak and Squaw Peak. The eastern side of the wilderness is a steep, abrupt escarpment of volcanic terrain of cliff bands and terraces. Very different from the east side are the western slopes. Heavily forested, steadily rising slopes furrowed by several drainages such as Mill Creek. The west side also includes a portion of a state game refuge.
Landscape
The Warner Mountain Range is a fault block range, with the Surprise Valley Fault on the east and the Likely Fault to the west. The steep escarpment on the east side of the range is the exposed side of the Surprise Valley fault. Geologists estimate that basalt lava flows occurred 15 to 30 million years ago, creating the Modoc Plateau which is a part of the larger Columbia Plateau. The breaking up of the crust occurred about 10 million years ago with large blocks moving and more volcanic lava flows, which created the mountains and block fault valleys of recent time. The landscape of today is not from mountain building but from the forces of erosion such as wind, water, and past glaciation.
Lakes and waterways
There are several lakes in the wilderness: Patterson, Mosquito, South Emerson, North Emerson, Clear Lake, Cottonwood, Cougar, Linderman, and Irons. Patterson Lake is the largest, highest in elevation and most visited. It also has a self-sustaining population of trout. Major streams draining the range are Poison Creek, Mill Creek, Parker Creek, and on the east side, Eagle Creek.
is the most popular activity, both day hikes and backpacking, with fishing, horseback riding, snowshoeing, and cross-country skiing making up the remainder. Dramatic views from the crest include Mount Shasta in the west, Modoc Plateau to the north, Surprise Valley in the Great Basin in the east and in the south, the Sierra Nevada range. There are of trails within the wilderness area, plus unmaintained pathways adding another. There are eight trailheads surrounding the wilderness and five campgrounds. Pepperdine Trailhead offers corrals for horses and stock parties. The Forest Service and many organizations encourage the practice of Leave No Trace principles of outdoor travel to minimize human impact on the environment.