more stats
1.6 miles
Distance
171 ft
Climb
-139 ft
Descent
00:12:42
Avg time
30 ft
Altitude change
4,455 ft
Altitude min
4,570 ft
Altitude max
4,471 ft
Altitude start
4,501 ft
Altitude end
0.4%
Grade
-30.1%
Grade max
17.7%
Grade min
4,423 ft
Distance climb
3,182 ft
Distance down
673 ft
Distance flat
00:12:42
Avg time

FS 641 Details

  • Activities
    • Mountain Bike
    • Gravel Bike
    • Adaptive Bike
    • Hike
    • Trail Running
  • Riding Area
    Keystone
    , South Dakota
  • Difficulty Rating
    Access Trail or Doubletrack Rate
  • Local Popularity
    75 in Mountain Biking [+]
    • 5 in Trail Running
    • 5 in Hiking
    • 75 in Gravel Biking
  • Trail Type
    Singletrack
  • Bike Type
    Gravel, Adaptive MTB
  • Direction
    Both Directions
    Popular Direction Shown
  • Dogs Allowed
    Yes

Forest Service 2-track. Can be used as a Fosters bailout or part of a loop.

Tags
Traditionally Indigenous Territory

Recent Activity on Trail

Past Week
  • 0 rides
  •  
6 Months
  • 4 rides
  • 9 miles avg distance
All
  • 9 rides
  • Last: Oct 7, 2026
update trails status or condition

FS 641 Trail Reports

statusdatedescription
Jul 9, 2025 @ 8:49am
Jul 9, 2025
Aug 27, 2022 @ 9:27am
Aug 27, 2022
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Status:
on Jul 9, 2025
Ideal
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      Directions to fs-641 trailhead (43.920810, -103.348270)
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      Frequently Asked Questions

      ▼ Where is FS 641 located?
      FS 641 is located in Keystone, South Dakota, United States. It is part of the Keystone trail network. The trailhead is located at coordinates 43.92081, -103.34827.
      ▼ What is the elevation gain for FS 641?
      FS 641 has 171 ft of elevation gain. The trail has 139 ft of elevation descent. The elevation ranges from 4,455 ft to 4,570 ft.
      ▼ Is FS 641 a point to point trail?
      FS 641 is not a point to point trail. The direction is Both Directions. The trail type is singletrack.
      ▼ How long is FS 641?
      FS 641 is 1.6 miles long. The trail type is singletrack.
      ▼ Are dogs allowed on FS 641?
      Yes, dogs are allowed on FS 641. Please keep dogs on a leash where required and clean up after them.
      ▼ How do I access FS 641? Where is the closest parking trailhead?
      The closest parking and trailhead locations to FS 641 are: View all parking locations in the area.
      ▼ How long does it take to ride FS 641?
      Based on recorded activities, it takes an average of 13 minutes to ride FS 641. The trail is 1.6 miles long. Actual times will vary based on fitness level, conditions, and pace. View recent activity logs for more details.
      ▼ How busy is FS 641?
      FS 641 is a very popular trail. There have been 36 recorded activities on this trail. The trail has received 38 check-ins. View recent activity on this trail.

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