Pine Bluff Loop is a 7.2 mile loop trail located near Nine Mile Falls, WA. The trail is rated as moderate and primarily used for mountain biking.
K first of all this is not just a bike trail. saw more hikers on it than bikers. this was mu first time on this loop so these insights are "what I'd do different" not definitive guide for riding this.
If you are riding this trail the #25 is your main route. There are side trails that seem to loop back into #25.
When I do this loop again I won't park at the trail head lot that Google takes you to. There is a pull off down the hill on the highway before you turn off on the dirt road to the parking lot. This pull off is right next to the where the #25 meets the highway. After this ride I know it will be much better to ride the trail the reverse of what I did. That is riding straight west as opposed to south dropping down into the river bed first. still don't know if the right thing was to take the paved traildown from the state park parking lot at the top. may there's someone out there that can post about that.
All in all a really fun ride.