The Rim trail is probably the least frequented route up to Wilson. The description doesn't appear in the Sierra Club's Hundred Peaks Section (HPS) Mt Wilson routes guide (but 5 others do) and a web page search will only register a couple of hits on trip reports. What it is surprisingly is that it is probably the nicest and easiest way to hike Mt Wilson short of driving up to the top by car. The entire approach combines the Sturtevant trail with the Gabrieleno Trail, finally meeting the start of the Rim trail at Newcomb Pass. The Rim trail hugs the north side of Wilson's east ridge as it gently climbs toward the summit area. The hike is reminiscent of wooded hikes in the High Sierra with only the sound of motorcycles on the Angeles Crest Highway and the occasional cluster of poodle dog bush disturbing that vision. After topping out, the trail wanders below the north side of the observatory complex before finishing just before the summit pavilion.
Follow the standard Chantry Flats approach by exiting Santa Anita Ave in Sierra Madre off the 210 freeway and driving north until it dead ends at the parking area. Expect parking to fill up by 7AM on weekends extending the hike to where ever you had to park along the road. Follow the route to the Sturtevant trail which heads down into the canyon from the lower parking lot.
The route follows the Sturtevant trail for the first 4 miles as it winds and climbs up the wooded Santa Anita Canyon. About a ¼ mile past the Spruce Grove trail camp, the Gabrieleno trail junction can be found on the right side. If you've made it to the Zion Mtn junction or Sturtevant Camp, you've gone too far. Head up the Gabrieleno trail for about 2 miles until you reach the wooded and well shaded Newcomb Pass (complete with picnic benches). From here, the Gabrieleno trail heads north down to the West Fork of the San Gabriel River, an old forest road heading south makes a spur connection to the Rincon Red Box forest road, and the Rim Trail heads west. Follow the Rim trail west for about 3 miles until you exit just past the observatory.
Other Essential Information
This is a good Spring through Fall route. Winter will present difficulties with snow and possibly ice due to its north facing aspect. Adventure Pass required