I remember that trail from the early 70's.
A few times some friends and myself with have someone drop us off there.
Armed with inflated tire tubes, we would scramble down the trail, and float/hike back to horse bridge.. never HIKED UP that trail, one way only.
Havent been down that trail since, probably 1975... With the road closed, I would imagine, NOONE goes down that trail anymore.. good luck finding it..