The Shasta-Trinity National Forest encompasses 2.2 million acres of far northern California: the largest national forest in California, covering Shasta, Trinity, Siskiyou, and Tehama counties in the volcanic and granitic mountain country north of the Sacramento Valley. The forest frames two of northern California's most iconic landscapes: the Mount Shasta volcanic cone rising to 14,179 feet in the east, and the Trinity Alps Wilderness: a compact but exceptionally rugged range of granite peaks, glacial lakes, and wild rivers in the west. The OHV trail system operates on designated routes in the non-wilderness portions of the forest, with the McCloud, Shasta Lake, Hayfork, and Mad River districts providing the primary riding terrain accessible from the Redding, Mount Shasta City, and Weaverville gateways. The Shasta Lake area in the forest's eastern reach, where the Sacramento River is impounded into California's largest reservoir, provides the most accessible riding terrain from the Redding market (population 95,000), with the Backbone Ridge, Shasta Bally, and Squaw Creek corridors offering forest road and designated OHV route riding on the lake's surrounding ridges. The Trinity side of the forest has a fundamentally different character: the Trinity River corridor and the mountains above it are wetter, more rugged, and less accessible, the Trinity Alps terrain is among the most remote in California, but the designated OHV routes on the Trinity side thread through a mixed conifer forest of Douglas fir, white fir, and sugar pine distinctly different from the drier Cascade terrain on the Shasta side. California OHV registration required. Shasta Lake Ranger District in Redding (530-226-2500) manages Shasta-side OHV trail status.