O'Leary Mountain Trail #3321 is a more to most difficult 9.1 mile hike at an elevation of 2,400 feet. Hikers are afforded excellent views of the McKenzie Balley , Three Sisters Peaks and Cougar Reservoir. The trial crossed McLennon, McDuff and O'Leary Mountain. There are some unique rock formations (pinnacles) along the way.
Directions 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.