Though not particularly steep, this dirt road is quite long, 9.2 miles one way. The road starts at the intersection with Pinecrest Drive and heads north out of the development on a mostly shadeless route dropping down and crossing a bridge over Eaton Canyon then climbing up the south facing side of the mountain. The trail intersects Eaton Canyon Path
early on at 0.2 miles and the old "equestrian trail" at 0.8 miles. Henninger Flats
is about 2.8 miles along the trail and is an excellent rest point. Although there is no water or flush toilets at Henninger Flats
, the shade and a visitor center might make you reconsider continuing on. There is also a campground for overnight use.
But continue on you must if you want to reach the summit of Mt. Wilson, a daunting 6.4 miles away. The road continues north from the upper campground area offering views of the flats below then enters a nicely shaded area of oak and bigcone spruce. About 1 mile above the flats there is a junction with the Idlehour Trail 12W16
at a switchback in the road. The road continues climbing and reaches a saddle. There is a spur trail heading south up to a high point with fine views of the Los Angeles Basin.
The road continues north with good views of Eaton Canyon then turns east through another welcomed shady area passing over a saddle and turning north with views into Little Santa Anita Canyon. At around 8 miles there is a junction at Manzanita Ridge with the Mt. Wilson Trail on the right. The road continues north along the steep eastern side of Mt. Harvard and reaches another saddle with the Mt. Wilson Summit Spur Trail
on the right. This trail saves about half a mile and leads directly to the large parking lot near the top. The road continues on the west side of the ridge and makes one long switchback ending at a junction with the Mt. Wilson Circle Road. To reach the parking lot and the pavilion, you need to go about 100' north and turn right through the gate if it is open.
There are nice views at the summit of Mt. Wilson and the Cosmic Cafe offers food and beverages (hours vary by season), but hiking to the top makes for a very long day.
Thanks to John McKinney, The Trailmaster, for sharing this trail description. To learn more about trails in California, check out his guides at The Trailmaster Store
There are numerous tree varieties in Henninger Flats
such as knob cone, Coulter, sugar, gray and Jeffery pine. Also Japanese black pine and Himalayan white pine. Oak and bigcone spruce provide areas of shade along the road above the flats. Chaparral of scrub oak, ceanothus, laurel sumac and manzanita are widely seen along the way. Poison oak is common in the shady areas. Watch for rattlesnakes.