Palomar Mountain is a mountain range in northern San Diego County, California, United States. It is most famous as being home to the Palomar Observatory and the giant Hale Telescope. It is also the location of Palomar Mountain State Park, a California state park. There are campgrounds for vacationers, as well as a campground for local school children. The park averages 70,000 visitors annually. High Point in the Palomar Mountain range is one of the highest peaks in San Diego County, at 6,140 feet (1,871 m), although it is still dwarfed by the higher 11,500 feet (3,505 m) San Bernardino Mountains a relatively-short distance north in San Bernardino County and Riverside County and the 14,500 feet (4,420 m) high Mount Whitney some 250 mi (402 km) further north.
South Grade Road, the stretch of San Diego County Route S6 going from State Route 76 to the summit, is popular among motorcycle riders and sports car drivers due to its challenging nature (over 20 hairpin turns over the distance of less than 7 mi (11 km)). According to fire department records, there have been 26 reported motorcycle injury accidents on the mountain this year. In 2004, the figure was 23. In 2003 there were 26.
The name "Palomar" comes from Spanish-speaking times, when Palomar Mountain was known as the home of band-tailed pigeons, thus the name Palomar, meaning "pigeon roost." During the 1890s, the human population was sufficient to support three public schools, and it was a popular summer resort for Southern California, with three hotels in operation part of the time, and a tent city in Doane Valley each summer.
At the base of Palomar Mountain range on S6 is Oak Knoll Campground, formerly known as Palomar Gardens. Palomar Gardens was made somewhat famous by an earlier resident George Adamski. Adamski had an observatory at Palomar Gardens and photographed objects in the night sky that he claimed were UFOs. Adamski co-authored Flying Saucers Have Landed in 1953, about his alien encounter experiences. The 1977 film The Crater Lake Monster had many scenes filmed on Palomar Mountain, including scenes shot at the summit restaurant, but not the scenes of the monster in a lake.Doane Valley, located within the State Park, is home to the Camp Palomar Outdoor School for 6th grade students in the San Diego Unified School District.