Williamson Peak is a nice day hike in the Cascade Lakes region west of Bend - located in the Three Sisters Wilderness area near Lava Lake.  The best way to reach the mountain is from the Lucky Lake Trailhead, just off Cascade Lakes NS Byway/Lava Lake Road.  From there the hike up to the summit is a little under 4 miles via the Senoj/Six Lakes Trail.  The trail grade varies from near flat to moderate with a total elevation gain of around 1600'.