Mount Wilson Observatory hosts public tours tracing century of cosmic discovery
Visitors can walk the historic site in the San Gabriel range, where early 20th-century telescopes helped define modern cosmology.
By Jason Kovalenko ·
The Mount Wilson Observatory in the San Gabriel Mountains opened its grounds to the public on Saturday, offering tours of the facilities that shaped modern astronomy. Located at 5,770 feet, the site provides a clear view of the sky due to its elevation and coastal breezes.
The observatory sits on land originally used by the Tongva people and later named Wilson’s Peak. In 1904, astronomer George Ellery Hale convinced philanthropist Andrew Carnegie to fund a solar telescope there. By 1917, the complex included a 60-inch and a 100-inch reflecting telescope, which were among the largest in the world at the time.
Docents guide visitors along a mule trail cut into the mountainside, noting that all equipment was hauled up by donkeys between 1904 and 1917. Inside the domes, visitors can view the massive instruments that pioneered the study of the universe's expansion. An informational sign states that every large telescope built today is a technological descendant of the Mount Wilson designs.
The solar telescope, housed atop a 150-foot tower, continues daily operations. A technician climbs the tower each morning to open the dome and records sunspot activity in a ground-level room. Current solar activity is low as the sun approaches the end of its 11-year cycle.
While much of the original equipment is now antiquated, the facility remains a site of historical importance. Photographs on the museum wall document visits by Albert Einstein in the 1930s and Stephen Hawking in later decades. Edwin Hubble also used the site’s instruments to confirm the expanding universe.
The observatory currently operates from 10 a.m. to 4 p.m. daily. Docent-led walking tours run at 11:30 a.m. and 1 p.m. on Saturdays and Sundays through the fall. Limited tours will continue in winter, alongside self-guided and private stargazing options.
Access is via the Angeles Crest Highway from the 210 Freeway at La Canada Flintridge. A U.S. Forest Service Adventure Pass is required for parking. The site also hosts concerts and lectures, with an on-site café and gift shop available to visitors.
