O'Leary Mountain Trail is a 18.2 mile lightly trafficked out and back trail located near Blue River, Oregon and is rated as difficult. The trail is primarily used for hiking and mountain biking and is accessible year-round.
Directions for those wishing to hike from Cougar Reservoir: From Blue River: Travel 3.5 miles east on Hwy. 126 to Aufderheide Drive (FS road 19). Continue on Aufderheide Drive to FS Rd. 1900-410 and travel for 2 miles to the powerhouse at Cougar dam. Just before entering the Corps of Engineers enclosure turn east on 1900-411 and proceed 2.5 miles. The trailheads common to the Castle Rock and Echo Trailhead.
Mostly downhill in the first 2 miles. The spikes uphill and downhill again. No views from the top to look at, just a lot of trees. great for bicyclist. Coming back was mainly steep uphill. Lots of wild rhodies, colorful conks, big trees.