Alpine is a census-designated place (CDP) in the Cuyamaca Mountains of San Diego County, California. Alpine had a population of 14,236 at the 2010 census, up from 13,143 at the 2000 census. The town is largely surrounded by the Cleveland National Forest and borders two reservations of the Kumeyaay Nation, Viejas and Sycuan, and the rural unincorporated areas of the city of El Cajon.
The community's name was suggested by a resident in the 1880s who said that the environment reminded her of her native country of Switzerland.
The small commercial district along Alpine Blvd. has seen some suburban development in recent decades, and it is surrounded by large stretches of less densely populated rural areas that began in the late 19th and early 20th century. Horse ranches and small farms are still common, along with open chaparral hillsides and riparian canyons.
Before its modern settlement, the area was part of the home of the Kumeyaay Indians, whose ancestors had lived here possibly as long as 12,000 years.
It sits on both sides of Interstate 8 at the eastern extent of the California coastal region and the western extent of the Peninsular Ranges, about 30 miles east of downtown San Diego, at an elevation of about 2,000 feet.
The location of Alpine is not precisely defined since it is an unincorporated area. According to the United States Geological Survey, it is at 32°50′6″N 116°45′59″W (32.8350521, -116.7664109), which is near the intersection of Alpine Boulevard and Tavern Road.