The Williams Valley Trail System consists of a number of interconnected loops, some of which are groomed for winter cross-country skiing, with others suitable for un-groomed backcountry skiing. During the spring, summer and fall, all are suitable for mountain biking, hiking, and horseback riding. The Williams Valley Recreation Area is closed to all motorized use year round. There is a snowmobile trailhead for winter access just beyond the boundary to the non-motorized area.
There are four trailheads to access the trail system - three along FR 249, and one at the junction of FR 249 and FR 276. The Williams Valley trails are rated according to difficulty: Easiest, More Difficult, and Most Difficult.
The Valley Trail (# 80A) is 2.8 miles long. It begins at Forest Service Road 249 and ends at a junction with the Sidewinder Trail (# 80G) at its east end. For winter use, the trail is groomed for interconnecting loops within the meadow.
The Lookout Meadow Loop Trail (# 80E) is 1.3 miles long. It begins at a junction with Valle Trail (# 80A) and ends looping back to (# 80A).
More Difficult Trails:
The Isolation Trail (# 80B) is 2.1 miles long. It begins at a junction with Valley Trail (# 80A) and ends at a junction of Yahoo Trail (# 80D) and Half Moon Trail (# 80C).
The Sidewinder trail (# 80G) is 0.9 miles long. It begins at Toboggan Trailhead and ends at a junction with Valley Trail (# 80A) at its west end.
The Half-Moon trail loops from the Lookout Meadow Loop (# 80E), past the junction with the east end of the Yahoo Trail (# 80D) around to the junction with Isolation Trail (# 80B) and the west end of #80D.
Most Difficult Trails:
Yahoo Trail (# 80D) is only .10 mile in length, but steep, and joins Half Moon Trail to the east, with a junction between Isolation Trail and Half Moon Trail to the West.
Up and Over Trail (# 80F) joins Lookout Meadow (# 80E) to the east with Isolation Trail (# 80B) to the west. source: fs.usda.gov