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South Fork Trinity Trail in Underwood

Features: This 8-mile round trip hike provides access to the proposed Underwood Wilderness, which straddles a segment of the South Fork Trinity Wild & Scenic River between Hyampom to the north and the Trinity River confluence to the south. With relatively easy access from Highway 299, this trail is popular with hikers and hunters. Because the trail follows a route high on the canyon wall, those interested in swimming must hike most of the trail to reach the river. Caution should be taken on the trail as it approaches, drops down into, and then climbs out of Hell’s Half Acre Creek. This trail segment consists of relatively narrow tread on steep slopes.

The proposed Underwood Wilderness is a 15,000-acre area of oak woodlands and conifer that offers a stunning spring wildflower display. The South Fork and its tributaries in the proposed Underwood Wilderness support threatened and endangered runs of coho and spring Chinook salmon, as well as fall Chinook salmon and steelhead. The area supports diverse wildlife, including black bear, mountain lion, river otter, and mink. Bald eagle and osprey are often seen fishing in the river.

Directions to trailhead: From Highway 299 near the confluence of the Trinity River and its South Fork, turn south on the South Fork Road (a.k.a. County Road 447). Drive south on the South Fork Road for about 12 miles past meadows, forests, small ranches, and a segment of the river popular with whitewater boaters, to where the road ends at the trailhead. Before your hike, be sure to inquire about the latest status of roads and trails by contacting the Forest Service’s Lower Trinity Ranger Station at (530) 629-2102.


Weather and road conditions can change in an instant. Always check with the managing agency before embarking on a trip. Always hike with a friend and carry a cell phone for emergencies. Bring plenty of drinking water, food, and clothing for changing weather conditions. Let someone know where you are going and when you intend to be back. Remember, California’s wild places are beautiful but they can also be dangerous to the unprepared and unwary. The California Wilderness Coalition assumes no liability if you intend to visit any of the wild places featured in our materials.