Centennial Trail via Hwy 87 is a 6.4 mile out and back trail located near Fairburn, South Dakota. The trail is rated as difficult and primarily used for hiking, trail running, and mountain biking.
OK first of all, my husband and I are very out of shape. In the past we were very in shape so take this review with that in mind. I concede maybe a really good mountain biker in great shape would be able to ride more of this trail. As a hiking trail I would rate it as demanding. But as a mountain biking trail it was impossible. There were several sections that even being a novice, I am certain no one could actually "ride" their bike down. The trails were so rocky that you had to be very careful and keep changing your line and never could build up any momentum making all the uphills impossible. At the highest point it has a sign saying riders must dismount, doesn't say horses or bikes, so we assumed both? Well that was just dragging or walking or lifing the bike down a long series of switchbacks made up completely of large rocks that was indeed I am sure not rideable. So we finally after 3 hours made it the 4.3 miles from Badger Hole TH to French Creek TH and decided we would have to go home by road. MapMyRide said we'd rode 5.66 so not sure where all the extra came from unless it was additional from Legion Lake to TH but I don't think that was 1.3 miles. This was meant to be a 2 hour casual mountain bike ride, some technical I expected and tough descents. Instead it was more of hike while pushing a bike. So the road home when we finally found our way to 87 probably a couple miles mostly uphill, was another 3 miles uphill. BUT I can say this the last two miles back to Legion Lake on 87 was all downhill and quite thrilling. I had to ride my brakes to stay under 40 mph. I'm sure if I'd had my tri bike I'd have gone over 50 mph. So I enjoyed the end which wasn't part of the trail anyway. We didn't see any evidence of bikes ever using the trail either. No bike tracks anywhere. Very little horse activity maybe one in past week. And no pedestrians likely either.