Cedar Canyon, San Ysidro Mountains

The Mountain Empire is a rural area in southeastern San Diego County, California. The Mountain Empire subregion consists of the backcountry communities in southeastern San Diego County. The area is also sometimes considered part of the East County region of San Diego County.

Rancho Jamul was a 8,926-acre (36.12 km2) Mexican land grant in present-day San Diego County, California given in 1829 by Mexican Governor José María de Echeandía to Pío Pico. In 1831 Governor Manuel Victoria reconfirmed the grant to Pío Pico. The grant extended from present day Jamul southeast to Dulzura. It is currently the 5,600-acre Rancho Jamul Ecological Reserve, operated by the California Department of Fish and Wildlife.

The San Ysidro Mountains are a mountain range in southern San Diego County, California, and Baja California, Mexico. The mountains are a rugged coastal foothill range of the Peninsular Ranges system. Major peaks include the highest summit of the range, Otay Mountain, and the Cerro San Isidro which forms the southern extrusion of the range on the Mexican side of the border. The majority of the range is within the Otay Mountain Wilderness area, in the United States.

Otay Mountain is a mountain in San Diego County, California. It is the highest summit of the San Ysidro Mountains. The mountain is located in the Otay Mountain Wilderness area. The Mexico-United States border runs along the south face of the mountain.

The Otay Mountain Wilderness is a U.S. Wilderness Area in San Diego County, California, 12 miles east of the community of Otay Mesa and just north of the Mexico-U.S. border. Some parts of the wilderness area rise quickly from sea level, reaching a peak of just over 3,500 feet (1,100 m) at the summit of Otay Mountain. Wilderness status was conferred on October 7, 1998, effectively preserving 18,500 acres under protection of the Wilderness Act, a component of the National Wilderness Preservation System. The legislation was signed by President Bill Clinton: 306  on December 11, 1999. The wilderness is managed by the Bureau of Land Management.

Hollenbeck Canyon Wildlife Area is located near Jamul and Dulzura in California. The former cattle ranch was designated a wildlife area in 2001, and forms a wildlife corridor between Otay Mountain Wilderness and Jamul Mountains under the protection of the California Department of Fish and Wildlife. The approximately 6,100-acre area is open to the public for activities including hunting, equestrian use, hiking, mountain-biking, and (hunting) dog training.

The Jamul Mountains are a mountain range of the Peninsular Ranges System. They are located in southernmost San Diego County, Southern California. The Mexico–United States border is nearby to the south. There is a trail starting at Upper Otay Lake that leads over the western part of the range.

The Jamul Indian Village of California is a federally recognized tribe of Kumeyaay Indians, who are sometimes known as Mission Indians.

The Jamul Casino is a Native American gambling enterprise run by the Jamul Indian Village on their 6-acre reservation in Jamul, California. It was formerly the Hollywood Casino Jamul-San Diego. The president and general manager is Mary Cheeks.The casino has 1,700 slot machines and 40 table games. It is located 20 miles east of downtown San Diego.

Lyons Peak is a prominent mountain in San Diego County, California. The top of the mountain is enclosed in an almost rectangular patch of the Cleveland National Forest. An old fire lookout tower is located at the peak. Lyons Peak is located on restricted land and trespassing is prohibited. The peak's toponym honors Nathaniel Lyon (1818–1861). As an army captain, he passed by the peak in 1851 while scouting a new route east to the desert.

Lower Otay Reservoir is a reservoir in San Diego County, Southern California. It is flanked by Otay Mountain to the southeast, the Jamul Mountains to the east, Otay Lakes Road and Upper Otay Reservoir to the north, and the city of Chula Vista to the west. The reservoir is formed by impounding the waters of the Otay River, behind Savage Dam, completed in 1918, and is also the terminus for the second San Diego Aqueduct, which transports imported water from the Colorado River. The dam and reservoir are owned by the City of San Diego.

Savage Dam is a dam across the Otay River in the San Ysidro Mountains of southwestern San Diego County, California. It is a concrete arch gravity structure 149 feet (45 m) high, and serves to store water from the San Diego Aqueduct's third pipeline for backup municipal uses in the San Diego metropolitan area. It is just over 6 miles (9.7 km) southeast of Chula Vista and 4 miles (6.4 km) north of the United States-Mexico border. The dam is named in honor of H. N. Savage, who directed its construction.The dam was originally completed in 1897 as an earthfill and steel structure called the Otay Dam by the Southern California Mountain Water Company to provide water storage. However, in 1916, heavy rains supposedly brought on by Charles Hatfield, a "rainmaker", hired by the city of San Diego to put an end to a drought, caused the dam to burst. The failure sent a wall of water 40 feet (12 m) high downstream, destroying buildings and bridges, and washing thousands of tons of sediment and wreckage into San Diego Bay. Eleven Japanese American farmers were killed. The dam was rebuilt as Savage Dam in 1918, and has functioned properly since.