Mount Wilson

Mount Wilson occupies a place of renown in scientific history. The observatory, founded by George Ellery Hale in 1904, became the world’s foremost astronomical research facility. The 100-inch Hooker telescope, the most powerful in the world for decades, went into service in 1917. From this telescope Edwin Hubble discovered that there were galaxies beyond the Milky Way, developed the Big Bang model and measured the expansion of the universe, and Albert Michelson measured the speed of light. You can read more about the history of Mount Wilson at mtwilson.edu/history. Mount Wilson is still on the cutting edge of astronomy with its CHARA array, the domes and white towers that you can see on your hike up.

Hikers usually reach the summit then return, but there are many interesting things to do on Mount Wilson. The 60″ and 100″ telescopes are open for public visits, and there is an interesting museum and public events. At the summit there is a covered picnic area where you can use the restrooms, refill your water, and have lunch at the Cosmic Cafe on weekends.

There are five official HPS routes and many other routes and route variations. Route 1 is a drive-up. Route 2 follows the Gabrieleno Trail from Chantry Flat; sights include Sturtevant Falls and historic Sturtevant Camp. Route 3, the Upper Winter Creek Trail also starts from Chantry Flat, passes Hoegees Camp and joins Route 2 at Sturtevant Camp. These routes are shady and scenic and there are numerous variations, including the Lower Winter Creek Trail (see the map). Route 4 is the Mount Wilson Toll Road, over which the mirror for the Hooker Telescope was gingerly transported to the summit. It is a gentler road walk. Route 5 is the classic and very popular Mount Wilson Trail that starts in Sierra Madre. This is the historic site of Lizzie’s Trail Inn that still exists as a small museum and is worthy of a visit. There are bathrooms at the trailhead. The trail ascends gradually and during most of its course ascends Santa Anita Canyon with marvelous views. At 1.7 miles a short use trail goes down to the stream, dubbed “First Water”. Routes 3 and 5 join at Manzanita Ridge, where you can rest on a bench overlooking the city and chat with other hikers. Some people stop here; it is a worthy destination in itself. The trail then joins the toll road for a walk to the summit. You can save some road walking by leaving the road 0.7 miles after Manzanita Ridge and climbing a use trail up the ridge to the HPS summit. On the map you will find several route variations and additional minor peaks (Jones Peak, Mount Zion, Hastings Peak and Mount Yale, named by angry Yale alumni after nearby Mount Harvard received its name).

Routes 2 and 3, the Gabrieleno and Winter Creek Trails and surrounding areas burned in the 2020 Bobcat Fire and remain closed as of June 2024. The Chantry Flat trailhead is also closed for construction. There is no projected reopening date.