Here are a couple of pics from my '97 FS map:
The main Rd running across the middle of this pic is Mill Creek Rd. Coming from The Dalles, SG is the first
road to the left after
you hit gravel. It appears to head down into somebodies back field, but actually skirts it right as you approach the creek, which, when you're at the edge of, the way to proceed becomes quite clear.
This shows SG as in runs up and along the Eastern Ridge of Blackburn Canyon into TD watershed.
I would go again, but I don't have the appropriate machine......
.....or do I??