|Location||Tehama County, California, Sierra/Cascade region|
|Nearest city||Red Bluff|
|Coordinates||40°08′05″N121°45′19″W / 40.13472°N 121.75528°W Coordinates: 40°08′05″N121°45′19″W / 40.13472°N 121.75528°W|
|Area||41,339 acres (167.29 km2)|
|Governing body||U.S. Forest Service and Bureau of Land Management|
The Ishi Wilderness is a 41,339 acre (167 km2)  wilderness area located on the Lassen National Forest in the Shasta Cascade foothills of northern California, United States. The Ishi Wilderness is located approximately 20 miles (32 km) east of Red Bluff. The wilderness was created when the US Congress passed the California Wilderness Act of 1984. The land is etched by wind and water, and dotted with basalt outcroppings, caves, and unusual pillar lava formations. The land is a series of east-west running ridges framed by rugged river canyons, with the highest ridges attaining elevations of 4,000 feet (1,200 m). Deer Creek and Mill Creek are the principal drainages and flow into the Sacramento River.
The Ishi Wilderness is the only protected area in California that preserves a significant portion of the Sierra/Cascade foothill region of the southernmost Cascade Ranges. 
Ishi is the name given by anthropologist Alfred L. Kroeber to the last surviving Native American from the Yahi Yana tribe. The Yahi Yana tribe had lived in the area for over three thousand years. Sometime after 1850, white settlers moving into the area killed all but a few of the Yahi. A few escaped and hid for years in the harsh wild country.
The sun-baked south slopes are covered with chaparral brush. Pines and oaks thrive on the moister slopes facing north and lush damp forests line the river banks. This area is home to pine clusters, dense areas of ponderosa pine growing on terraces in river cut canyons.
The largest migratory deer herd in California, the Tehama deer herd, winters in this wilderness area. Wild hogs, mountain lions, black bears, coyotes, bobcats and rabbits also live here. A State Game Refuge, where hunting is not permitted, occupies most of the Ishi Wilderness.
A variety of raptors including hawks, eagles, falcons, and owls nest in the rock cliffs. Wild turkey, quail, mourning doves, canyon wrens, band-tailed pigeons, and many songbirds are frequently seen.
The US Forest Service reminds visitors to the Wilderness to respect the record of the Yahi Yana Indians. All archaeological and historical sites and artifacts are protected by federal law and should not be disturbed.
The Leave No Trace principles of wilderness travel are highly encouraged also by both the Forest Service and the Bureau of Land Management (the BLM manages a small portion of the wilderness-240 acres (97 ha).)
Special fishing regulations are in effect for fishing in Deer and Mill Creeks, home to many fish species. A valid California fishing license is required.
Ishi was the last known member of the Native American Yahi people from the present-day state of California in the United States. The rest of the Yahi were killed in the California genocide in the 19th century. Ishi, who was widely acclaimed as the "last wild Indian" in the United States, lived most of his life isolated from modern North American culture. In 1911, aged 50, he emerged at a barn and corral, 2 mi (3.2 km) from downtown Oroville, California.
The Shasta–Trinity National Forest is a federally designated forest in northern California, United States. It is the largest National Forest in California and is managed by the U.S. Forest Service. The 2,210,485 acre forest encompasses five wilderness areas, hundreds of mountain lakes and 6,278 miles (10,103 km) of streams and rivers. Major features include Shasta Lake, the largest man-made lake in California and Mount Shasta, elevation 14,179 feet (4,322 m).
Lassen National Forest is a United States national forest of 1,700 square miles (4,300 km2) in northeastern California. It is named after pioneer Peter Lassen, who mined, ranched and promoted the area to emigrant parties in the 1850s.
Deer Creek is a 60-mile-long (97 km) southwestward-flowing stream in Northern California that flows through Tehama County, California. It is an eastside tributary of the Sacramento River. As one of only three remaining Sacramento River tributaries supporting native runs of the genetically distinct Central Valley spring-run Chinook salmon, it is a stronghold for this state and federally endangered fish as well as other salmonids.
The Yana are a group of Native Americans indigenous to Northern California in the central Sierra Nevada, on the western side of the range. Their lands, prior to encroachment by white settlers, bordered the Pit and Feather rivers. They were nearly destroyed during the California genocide in the latter half of the 19th century. The Central and Southern Yana continue to live in California as members of Redding Rancheria.
Jennie Lakes Wilderness is a protected area in the Sierra Nevada, in Tulare County, California. It is located 60 miles (97 km) east of Fresno and managed by the US Forest Service. Jennie Lakes Wilderness is about nine square miles within the Sequoia National Forest, that was established by the California Wilderness Act of 1984, and added to the National Wilderness Preservation System.
The South Warner Wilderness is a federally designated wilderness area 12 miles (19 km) east of Alturas, California, United States. It encompasses more than 70,000 acres (283 km2) of the Warner Mountains. It is within the Modoc National Forest and managed by the US Forest Service. Elevations range from 5,000 feet (1,500 m) to 9,895 feet at Eagle Peak.
The Snow Mountain Wilderness is a 60,076-acre (243.12 km2) federally designated wilderness area located 65 miles (105 km) north of Santa Rosa, California, USA in the Mendocino National Forest. The U.S. Congress passed the California Wilderness Act of 1984 which created 23 new wilderness areas including Snow Mountain. It lies within the North Coast Range of mountains.
The Domeland Wilderness is a federally designated wilderness area located 55 miles (89 km) northeast of Bakersfield, California USA. It encompasses 130,081 acres (526.42 km2), is jointly managed by the U.S. Forest Service and Bureau of Land Management (BLM) and is mostly within the Sequoia National Forest.
The South Sierra Wilderness is a federally designated wilderness area in the Southern Sierra Nevada, in eastern California. It is located 65 miles (105 km) northeast of Bakersfield, and is southwest of Owens Lake and Olancha.
The Golden Trout Wilderness is a federally designated wilderness area in the Sierra Nevada, in Tulare County and Inyo County, California. It is located 40 miles (64 km) east of Porterville within Inyo National Forest and Sequoia National Forest.
The Monarch Wilderness is a federally designated wilderness area located 70 miles east of Fresno, California, in the Sierra Nevada mountain range. It encompasses 44,896 acres (181.69 km2) within both the Sequoia National Forest and the Sierra National Forest and is managed by the United States Forest Service. Elevations range from 950 feet (290 m) to 11,081 ft (3,377 m).
The Klamath Mountains ecoregion of Oregon and California lies inland and north of the Coast Range ecoregion, extending from the Umpqua River in the north to the Sacramento Valley in the south. It encompasses the highly dissected ridges, foothills, and valleys of the Klamath and Siskiyou Mountains. It corresponds to the Level III ecoregion designated by the Environmental Protection Agency and to the Klamath-Siskiyou forests ecoregion designated by the World Wide Fund for Nature.
The Kaiser Wilderness is a federally designated wilderness protected area located 70 miles (110 km) northeast of Fresno in the state of California, USA. It was added to the National Wilderness Preservation System by the United States Congress on October 19, 1976. The wilderness is 22,700 acres (92 km2) in size, is one of five wilderness areas within the Sierra National Forest and is managed by the US Forest Service.
The Bucks Lake Wilderness is a 23,958-acre (97.0 km2) wilderness area located in the Plumas National Forest section of the Sierra Nevada, in northeastern California, United States.
The Yolla Bolly–Middle Eel Wilderness is a federally designated wilderness area in the Yolla Bolly Range of the southern Klamath Mountains and the Inner Northern California Coast Ranges, in Northern California.
The Carson–Iceberg Wilderness is a federal wilderness area located 80 miles (130 km) northeast of Stockton, California. It encompasses 160,000 acres (650 km2) and was designated by the California Wilderness Act of 1984. It protects an area of High Sierra landscape with elevations from 4,800 feet (1,500 m) to 11,462 feet (3,494 m) along the Sierra Mountains from Ebbetts Pass to Sonora Pass in the south. The US Forest Service manages the wilderness which is in both the Stanislaus National Forest and the Humboldt–Toiyabe National Forest.
The Mokelumne Wilderness is a 105,165-acre federally designated wilderness area located 70 miles (110 km) east of Sacramento, California. It is within the boundaries of three national forests: Stanislaus, Eldorado and Toiyabe. First protected under the Wilderness Act of 1964, the Mokelumne's borders were expanded under the California Wilderness Act of 1984 with the addition of 55,000 acres. The wilderness takes its name from the Mokelumne River, which was named after a Mi-wok Indian village located on the riverbank in California's Central Valley.
The Mount Shasta Wilderness is a 38,200-acre (155 km2) federally designated wilderness area located 5 miles (8.0 km) east of Mount Shasta City in northern California. The US Congress passed the 1984 California Wilderness Act that set aside the Mount Shasta Wilderness. The US Forest Service is the managing agency as the wilderness is within the Shasta-Trinity National Forest. The area is named for and is dominated by the Mount Shasta volcano which reaches a traditionally quoted height of 14,162 feet (4,317 m) above sea level, but official sources give values ranging from 14,104 feet (4,299 m) from one USGS project, to 14,179 feet (4,322 m) via the NOAA. Mount Shasta is one of only two peaks in the state over 14,000 feet (4,300 m) outside the Sierra Nevada Mountain Range. The other summit is White Mountain Peak in the Great Basin of east-central California.
The Castle Crags Wilderness is a 12,232-acre (49.50 km2) wilderness area in the Castle Crags rock formations of the Trinity Mountains, and within the Shasta-Trinity National Forest, in northwestern California. It is located in Siskiyou County and Shasta County, 40 miles (64 km) north of Redding and south of Mount Shasta City.