Mount Laguna Observatory Summer Visitors Program Returns
- Susan Heavilin
- 3 hours ago
- 4 min read
Are you a stargazer? Then you'll be happy to hear that Star Parties are back!
SDSU MOUNT LAGUNA OBSERVATORY
Summer 2026 Schedule
Saturday Nights
May 23 - August 15
Star parties are back at Mount Laguna with the return of the Summer Visitors Program at the Mount Laguna Observatory.
The public programs will be held on Saturday nights from 8 to 11 p.m., May 23 through August 15, with a special bonus mid-week viewing scheduled for Wednesday, August 12.
Operated by the San Diego State University Department of Astronomy in partnership with the United States Forest Service, the outreach initiative has been connecting the public with the cosmos in various forms since the observatory’s dedication in 1968.
According to Dr. Robert Quimby, MLO Director and Professor in the SDSU Department of Astronomy, each event will feature a public lecture at the Harrington Visitors Center. If weather permits, the lecture will be followed by direct stargazing through the observatory’s 0.5-meter (21-inch) Reginald Buller telescope. While MLO boasts larger instruments for deep-space science, the Buller telescope is specifically dedicated to instructional use and public outreach.
Nestled in the Cleveland National Forest roughly 45 miles east of downtown San Diego, MLO sits at an elevation of 6,100 feet. The site is highly regarded by astronomers for its pristine dark skies, exceptional atmospheric conditions, and vital distance from city light pollution.
Beyond its public outreach, MLO is a premier research and training facility.
The mountain hosts an impressive array of cutting-edge technology, including the 1.25-meter Phillips Claud Telescope, which is used alongside the observatory’s 1.0-meter and 0.6-meter Clifford Smith telescopes to collect critical data on the age of and distance to star clusters.
MLO also houses one of only two EvryScopes in the world. This specialized multi-camera array monitors the entire accessible sky simultaneously, making it an exceptional tool for detecting stellar activity and eclipsing binaries (co-orbiting star systems).
Because the observatory is a functioning research station located in a rugged forest environment, organizers emphasize that safety and preparation are paramount for attendees.
Visitors are advised to bring a small flashlight and park at the lower visitors parking lot located on Morris Ranch Road, follow the short trail from the parking lot to Observatory Road, and from there, look for the white dashes painted on the ground and follow them for a quarter-mile uphill to the Harrington Visitors Center. Note that visitors must remain on the designated road at all times.
Morris Ranch Road is located off Sunrise Highway (S1) between mile markers 21.5 and 22, directly across from the Wooded Hill Campground sign.
All stargazing events are weather-permitting. For daily operational updates, weather delays, or cancellations, visitors should call the observatory hotline at (619) 594-1415 before making the drive up the mountain.
East County News Service | May 17, 2026
History of Mount Laguna Observatory
Mount Laguna Observatory (MLO) is an astronomical observatory owned and operated by San Diego State University (SDSU). The telescope was operated in partnership with the University of Illinois at Urbana-Champaign (UIUC) until 2000.
MLO is located approximately 75 kilometers (47 mi) east of downtown San Diego, California (USA) on the eastern edge of the Cleveland National Forest in the Laguna Mountains on the SDSU Astronomy Campus near the hamlet of Mount Laguna.
MLO was dedicated on June 19, 1968, seven years after SDSU's Department of Astronomy became an independent academic department of SDSU's College of Sciences. The dedication took place during the 1968 summer meeting of the Astronomical Society of the Pacific.
Currently SDSU is working with University of Kansas (KU), and UNC Chapel Hill on various projects.
MLO also engages with the public through a series of scientific outreach efforts such as the summer visitors program (SVP). SVP's take place on select dates throughout the summer months (May - August, starting typically on Memorial Day weekend) and include scientific demonstrations in the museum / gift shop, an introductory lecture on astronomy, and a stargazing session using a myriad of telescopes such as the 0.52 m (20 in) Reginald Buller 21-inch Visitors' Telescope. The SVP is predominantly run by graduate students within the SDSU Astronomy Master's program.
Mount Laguna Observatory Telescopes
There are four telescopes in use.
The 1.06 m (42 in) MLO 40-inch Telescope is a Cassegrain reflector built by Astro Mechanics in 1966. It was originally fitted with a 1.02 m (40 in) primary mirror which has since been replaced. It is known informally as the Illinois telescope because it was located at UIUC's Prairie Observatory until 1981.
The 0.6 m (24 in) Clifford Smith 24-inch Telescope is a Cassegrain reflector. It was built by the SDSU Department of Astronomy and used at the main campus from 1961 to 1966. In 1971 it was installed at MLO after modifications.
The 0.52 m (20 in) Reginald Buller 21-inch Visitors' Telescope was built in 1950 by J.W. Fecker, Inc. It was donated to SDSU by Reginald Buller and dedicated at MLO in 1988. It is used primarily by students for direct viewing, and for outreach.
The EvryScope is a Multiple aperture (24x) .062 m (2.4 in) survey telescope taking Appx. 8000 square degree fields every two minutes. It is a collaboration between SDSU and UNC.
Information from Wikipedia
How To Find Mount Laguna Observatory
Places to Stay Overnight
Research Sources: San Diego State University (SDSU), Mount Laguna Observatory, East County News Service, Wikipedia, Facebook, Google, Recreation.gov, Laguna Mountain Lodge.
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