Deerhorn Valley

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.

Barrett Dam is a concrete arch-gravity dam in southern San Diego County, California, United States, forming Barrett Lake on Cottonwood Creek. The dam is part of the city of San Diego's local water supply system.

Dulzura (Spanish for "Gentleness" or "Sweetness"; Kumeyaay: Ha-pe-was) is an unincorporated community in San Diego County, California.

The Gate Fire was a wildfire that burned in the Dulzura area southeast of Jamul along Highway 94 in the southern part of San Diego County, California in May 2017. Within the day, the fire spread from an initially reported 10 acres (4.0 ha) to then 1,500 acres (610 ha) in a matter of a few hours, as the fire was pushed by strong winds and dry grasslands mixed with chaparral. The wildfire resulted in evacuation of 500 campers from the Pio Pico RV Resort and Campground. Highway 94 was also closed to the public due to the fire. The fire was named the Gate incident due to its proximity to a landmark pink gate in the Dulzura area.

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 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.

The Laguna Fire, also known as the Kitchen Creek Fire or the Boulder Oaks Fire, was a 175,425-acre (70,992 ha) wildfire that burned from September 22 to October 4, 1970, in the Laguna Mountains and East County region of San Diego County in Southern California. It was one of many wildfires in a massive conflagration that spanned across the state from September 22 to October 4, 1970. At the time, it was the second-largest fire in the recorded history of California after the 1932 Matilija Fire (not counting the Santiago Canyon Fire in 1889, which experts estimate burned approximately 300,000 acres (120,000 ha)).

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.

Cedar Canyon is a valley of the San Ysidro Mountains in San Diego County, California, extending from the northern slopes of Otay Mountain in the south to Otay Lakes Road in the north. Part of it is in the Otay Mountain Wilderness.

Loveland Dam (also called Sweetwater Falls Dam) is a dam across the Sweetwater River in San Diego County, California. The dam forms long, narrow Loveland Reservoir which stores 25,387 acre-feet (31,314,000 m3) of water. It is operated primarily for flood control and municipal water storage in conjunction with downstream Sweetwater Dam but the reservoir is also open to the public for fishing.The dam stands 203 feet (62 m) high and spans 765 feet (233 m) across the narrow gorge of the Sweetwater River, 2.4 miles (3.9 km) south of Alpine. It is built entirely of concrete and has a thin arch design. Loveland is the younger of the two dams on the Sweetwater River; the other, Sweetwater, was built in 1888 while Loveland was only constructed in 1945. It is named after Chester H. Loveland, president of the California Water and Telephone Corporation, the firm that built it. The Loveland Reservoir is considered a better water storage facility than Sweetwater because of its much smaller surface area (454 acres compared to 960) and comparable capacity, thus it is less vulnerable to evaporation.

McGinty Mountain is a gabbroic mountain located in San Diego County, California near Jamul. Because of the gabbroic soil, the mountain supports numerous rare and endemic plant species, including half of California's population of the Dehesa nolina (Nolina interrata). The mountain belongs to an ecological preserve collectively managed by The Nature Conservancy, the California Department of Fish and Wildlife, and the San Diego National Wildlife Refuge. The mountain is accessible through a 4.7 mi (7.6 km) long out-and-back hiking trail.

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.