Bryon Boyce said
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.

I was thinking about that, but it doesn't seem to fit for two reasons:

1. As far as I know, the Bagby trail doesn't start as a road
2. The Bagby trail has 2 trailheads (north and south)

I'm stumped....

Not Bagby, continue going northwest. The trailhead is unmarked, when I said 'dug deep', it didn't mean it was obscure, just that I had forgotten about hiking the trail as far back as I did.

ill try another hint, the first part of the trail goes through a recent (<10yr) thin. It's on a paved road.......

I'm still stumped....Paved road?  Wilderness?  Starts as an old road?  2300'?  And NW of Bagby?

Are you sure it is in district?  Does the trail appear on the trail list here?

OK, after some more thinking - I think I got it - Hillockburn.  That seems to match all your criteria (except that is more north than northwest).  And I'm wondering if that section is the area near where you bailed off downhill to see the upper falls?

Bingo!