We spent a few days in Lander, Wyoming which lies on the east slope of the Wind River range. While there we made a quick visit to Sinks Canyon State Park. Camping is available at the state park, but is very limited for larger vehicles.
It would be spectacular to visit during the spring runoff rather than in fall.
Your geology lesson for today from outside the visitor center (already closed for the season):
You can hike from the sink to the rise. The river is underground at this point.
The canyon walls.
At the rise: fish!
Feed the fish. And the birds, please.