If you’re coming into Dayton on Hwy 12 from the direction of Walla Walla, drive practically all the way through town. Towards the end you’ll go up a rise and ahead you’ll see the road curve to the left onto a bridge. Before that, you want to take a right on the road that splits off from the main (the Patit Rd); there’s some iron Lewis & Clark cutouts just a little ways on from the turn.
If you’re coming into town from the Lewiston direction, you’ll curve up and around on a bridge next to the old Seneca plant. Right on your left as you near the end of the turn, you’ll see the iron cutouts marking the turn onto the Patit Rd, and you’ll take a left there.
From there, you follow the Patit Road out and around; you’ll pass the place where Lewis & Clark camped, and after a few miles, there’ll be a road that cuts off to the right– Range Grade. You’ll have to watch for it; it isn’t very well marked. Take that, and you’ll cross a little bridge. Instead of going straight, take an immediate left, and drive through the barbed wire gates — they’ll be open — and you’re there.
It is a paved road the entire way, right up until you turn in the Range gates.