“The trail around Hagg Lake is a close-to-Portland ride, with over 13 miles of singletrack.
— Tyler Bump
The park is open year round, from sunrise to sunset.
There is only one trail which circumnavigates Hagg Lake. There is no real preferred direction, but this article describes riding it CCW.
Many folks like to go just across the dam (left right after entering the park), but I prefer to go to the next (smaller) parking lot past the big dirt one. Then I ride back across the dam.
There are quite a few places where hiking/fishing trails cross the loop trail, but if you take a wrong turn you can't go very far.
NOTE: There is an access fee. See need to know section below for details. This trail offers a lot of amazingly fun riding as well as a little taste of each of the worst things western Oregon has to offer for mountain bikers.
1. The open, sun drenched and low lying meadows are hot and often overgrown in the summer. It isn't humanly possible to keep up with the overgrowth in these areas. If there is a sign that says "Ecologically Sensitive" find the nearest spur and ride up to the road and bypass it.
2. Watch out for spurs that descend to the lake or road, and spurs for the frisbee golf course. It's easy to make a wrong turn, but it's also easy to backtrack and get back onto the main trail.
3. Watch out for hikers on the trail! There are fishermen, swimmers and regular hikers on the trail - the swimmers and fishermen often don't pay attention to others on the trail, and fishermen will sometimes setup their gear right on the trail.
4. In wet months, the trail has lots of muddy pot holes, and stretches of muddy trail. Try riding the logging roads or the trails near Gale's Creek Campground instead.
The Clockwise Loop:
Park in the large parking lot on your right, just across the dam.
From there, ride down the road to a small paved pull-out parking area, and head down the trail.
Soon you'll cross a bridge that NWTA helped construct, then you'll come to a picnic area and the large Boat Ramp C area, where there are bathrooms and a food vendor (and water).
Continue on the south side of the lake, going clockwise, until you come to the west end of the lake, where the trail dumps you out on the road.
Continue around the west end of the lake, going about 1/4 mile until you see the trail jump into the woods again. This enters the Butterfly area. Be careful to stay on the trail here.
Continue until Boat Ramp A. You are dumped on the road a couple of times, but carefully ride along the right side of the road and jump back on the trail when you see it.
After Boat Ramp A it's only a mile or two to the damn, going behind the Ranger Station (fenced with chain link). Ride back across the dam and you are at your car with a smile!
This trail was originally created with help from PUMP (our bike club before being rebranded) about 10 years ago.