Three Corners Rock, aka 3CR, is an OAB back-country epic with some of the toughest climbs, lots of tight-switchbacks and a big creek crossing. You're rewarded for all that hard climbing with gorgeous views of Mt St Helens, Mt Rainer, Mt Adams and Mt Hood.
Most of the trail is in deep woods so it holds up well in winter, but there are quite a few areas where water has eroded the trail, making it really challenging.
Start from the Washougal Fish Hatchery, which has free parking next to the river, and ride up the road to the trailhead to get a nice warm up and enjoy views of the Washogual River.
Need To Know
There is a 20 foot creek crossing halfway to the turn around point. Bring enough calories and water, this trail is much harder than it seems.
For those of us in Portland, Three Corner Rock is about the closest bonafide mountainous singletrack.
Starting from the river at around 1000 feet, it climbs nine miles up to a rock outcropping that sits at 3800 feet. 2800 feet over nine miles? Easy, right? Except that in the first five miles, the trail climbs up and over a ridge and then drops down to a stream crossing before climbing back up to 2000 feet again only to drop down to 1500 feet where the bridge is out over Stebbins Creek. That leaves the final push to the summit a 2300 foot climb in four short miles. As if that's not enough climbing, don't forget that once you bomb back down to the creek after taking in the stunning and panoramic view of the surrounding mountains: Silver Star, Mt Adams, Mt Hood, St Helens and a ribbon of the mighty Columbia looking down the valleys at Portland; and after crossing the cold stream you'll still have two more moderate climbs to get back.