This proposed wilderness is located along the canyon of the South Fork Trinity Wild and Scenic River.
Recreational opportunities abound in Underwood with boating, hiking and wildflower viewing in the spring followed by swimming in its many pools during the summer. One can often see salmon and steelhead holding in these same pools in the summer and spawning in the fall. The proposed wilderness hosts a fall run of Chinook salmon as well as a lesser run of coho salmon.
Fishing opportunities for trout attract many anglers. For some 5 miles, the South Fork Trail winds through the steep and rugged terrain above the river. This trail is popular with hunters and hikers, and is used for river access by anglers. Spring wildflower displays can often be quite stunning.
South Fork Mountain, which forms the approximate western boundary of the proposed wilderness, is notable for being the longest ridge found in the western hemisphere.
Underwood provides important habitat for mountain lion and bear, as well as raptors such as eagle and osprey. Along the river, both otter and mink are found.