Mt Wilson Radio summit – Henninger Flats loop from Red Box

Mountain biking trails

United States

California

Los Angeles County

San Gabriel Mountains National Monument

Mt Wilson Radio summit – Henninger Flats loop from Red Box

Hard

4.7

(4694)

5,109

riders

Mt Wilson Radio summit – Henninger Flats loop from Red Box

04:32

39.4km

1,630m

Mountain biking

Hard mountain bike ride. Very good fitness required. The starting point of the route is right next to a parking lot.

Last updated: November 5, 2026

Tips

Your route passes through protected areas

Please check local regulations for:

Angeles National Forest

Waypoints

Start point

Parking

Get Directions

106 m

Haramokngna – American Indian Cultural Center

Highlight • Historical Site

The visitor center is across from the Red Box Trailhead parking area, with a natural stone viewpoint to the Pacific in the west. It was usually open on weekends and on holidays from 10am to 6pm. It is temporarily closed as of 2024. For current information see: haramokngna.org

Tip by

2.74 km

Sunrise view

Highlight • Viewpoint

Overlook to the east along the Mt Wilson Red Box road

Tip by

3.51 km

Observatory overlook

Highlight • Viewpoint

From this spot, you can see the observatory on Mount Disappointment, along with views of the San Gabriel Mountains and Valley.

Tip by

4.04 km

Mt Lowe gravel road

Highlight • Trail

Gravel track on former railway from Eaton Canyon to Mt Wilson

Tip by

6.57 km

Wilson Observatory overlook

Highlight • Viewpoint

Viewpoint to the east to the Wilson Observatory

Tip by

7.21 km

Mt Wilson Radio summit

Highlight • Summit

A short climb leads up to the Mt Wilson summit that's covered with telecommunications towers

Tip by

7.71 km

Mt Wilson Toll Rd

Highlight • Trail

Junction at the summit of Mt Wilson gravel road with the paved road at the gate to Mt Wilson Skyline Park

Tip by

17.5 km

Henninger Flats

Highlight • Viewpoint

Henninger Flats sits along the road with views of Altadena. You’ll pass by it while climbing the Mt. Wilson Toll Road and can take a moment to catch your breath while enjoying the views. The route features a steady climb with minimal shade, so it’s best to start early, especially in summer. At the top, enjoy panoramic views of the San Gabriel Valley and explore the area, which includes a visitor center, picnic spots, and a tree nursery.

Tip by

19.7 km

LA County Open Space

Nature Reserve

39.4 km

End point

Parking

Way Types & Surfaces

Way Types