An often overlooked ride on narrow singletrack. You'll put in some time pedaling up to rope swing intermission before racing back down to the start for a tidy 10-mile, out-and-back ride.
The start of this trail is found a few hundred feet north of Looking Glass Road (FSR #63) on a closed gravel road (shuttles are possible along this road).
The entrance of the trail is on the left, but it may be a little overgrown. From there, the trail is hard to miss. The singletrack starts off with a few steep climbs and gradually levels out into a gradual climb through dense forest on the edge of a slump (the sink the trail is named for).
The trail appears to come to an end in a clearing with no real markings, but some USFS maps show it continuing west on a doubletrack to reach Looking Glass Road (FSR #63) again. If you were to continue straight at the clearing (as mapped) the receding FSR #35 and then the Jubilee Lake Connector
lead to the pedestrian-only Jubilee Lake Trail #3230 on the southern end of water. While riding isn't allowed, you'll come out very near a popular rope swing so dismount and have a go!
On the way back, the ride is fast and flowy as it follows the smooth and narrow singletrack back to the start.