trail starts out as an old road.. Only has one trailhead

The only trail that comes to mind that starts on an old road that is in wilderness is Dickey Creek, but that doesn't remind me of Dickey Creek (although it has been several years since I've been there).

Go west young man.

This trail does bear similar characteristics to the beginning of Dickey on the map, though 

This photo was taken at about 2,300 ft..

Here's a wild-eyed guess - I haven't been on the trail in about 25 years.

The Bagby Trail 544. 2300 ft. would be a bit past the hot springs.