Black Hills National Forest · South Dakota, Wyoming
Deerfield Lake Loop
11 mi of trail, end to end · native material surface · trail No. 40L · trail class 3 · typical grade 12-20% · tread 24-36 inches wide · hiking, horse, bike
Picnic areas
Along the way Mountain City Picnic Area
Trailheads Deerfield Lake Loop Trailheads (Trail #40L) Drive there · Gold Run Trailhead Drive there
Deerfield Lake Loop Trailheads (Trail #40L) the Forest Service's write-up
This 10 mile trail encircles Deerfield Lake. From Reynolds Prairie you'll have great views of the lake. To the south, the trail winds through areas of tall pines and small meadows. This trail can be accessed from four trailheads: Custer Trail Trailhead, North Shore Trailhead, Hill Top Trailhead and the Gold Run Trailhead.
This trailhead on fs.usda.gov
Every trail in Black Hills National Forest
About this trail's facts
The lines are the US Forest Service's National Forest System trails layer (public domain), read 2026-10-16 and simplified for the map; the length is the line's, end to end, and the class, surface, grade and tread width are the forest's own entries where it publishes them - a forest that publishes the centreline alone has none. The trailheads and the points along the way are the Service's recreation points, and the write-ups its own recarea text, unedited. Heights come from USGS 3DEP through Terrain Tiles on AWS (Mapzen/Tilezen), read along each line and rounded; a short trail on steep ground can be off by a few tens of feet. Closures change: check the forest's own site before you go.
