Stony Ridge Observatory, San Gabriel Mountains National Monument

Stony Ridge Observatory is an astronomical observatory built by and for amateur astronomers in the mountains of Los Angeles County, California, in 1957. When installed, its 760 mm Newtonian-Cassegrain likely ranked as 8th largest of all telescopes in California, and one of the largest amateur telescopes in the United States. The telescope is designed so that one of four Newtonian foci, or a Cassegrain focus, can be used. Asteroids 10168 Stony Ridge, 144633 Georgecarroll and 327030 Alanmaclure, were discovered at the observatory, and other scientific research has been conducted there. The observatory also has a 12-inch Cassegrain telescope and a number of accessory items, including CCD cameras and computer equipment. ()