The Fourmile Basin Trail is accessed 1.7 miles up the Twin Lakes Trail #44
. At that point, Fourmile Basin goes right and Twin Lakes Trail #44
goes left. Both trails end at scenic mountain lakes.
After turning onto Fourmile Basin, you follow the logging road turned-singletrack for 1.5 miles. Beyond this point you'll be on the original pre-logging singletrack. At 2.4 miles, runners will arrive at the lake. Beyond this point the trail enters Recommended Wilderness and bikes are not allowed, and you're likely to see less traffic past here.
The lower parts of both Fourmile Basin and Twin Lakes were converted from logging road to singletrack by the Forest Service earlier this decade.