Rancho Santa Margarita is a city in Orange County, California, United States. One of Orange County's youngest cities, Rancho Santa Margarita is a master-planned community. The population was 47,853 at the 2010 census, up from 47,214 at the 2000 census. Although it is named for Rancho Santa Margarita y Las Flores, which was in San Diego County, the city limits fall within the borders of Rancho Mission Viejo. At 20 characters long, it is the longest city name in California.
The Santa Ana Mountains are a short peninsular mountain range along the coast of Southern California in the United States. They extend for approximately 61 miles (98 km) southeast of the Los Angeles Basin largely along the border between Orange and Riverside counties.
Arroyo Hondo is a northwestward-flowing 13.0-mile-long (20.9 km) river in Santa Clara County, California, United States, that lies east of Milpitas. The area is privately owned by the San Francisco Water Department and is closed to public access because of its usage as drinking water. Bounded to the east by Oak Ridge and to the west by Poverty Ridge, Arroyo Hondo empties into the Calaveras Reservoir where it joins Calaveras Creek. It is formed by the confluence of Smith Creek and Isabel Creek which drain the west and east slopes of Mount Hamilton, respectively.
Piru Creek is a major stream, about 71 miles (114 km) long, in northern Los Angeles County and eastern Ventura County, California. It is a tributary of the Santa Clara River, the largest stream system in Southern California that is still relatively natural.
Pilarcitos Creek is a 13.5-mile-long (21.7 km) coastal stream in San Mateo County, California, United States, that rises on the western slopes of the Santa Cruz Mountains and descends through Pilarcitos Canyon to discharge into the Pacific Ocean Half Moon Bay State Beach.
San Juan Creek, also called the San Juan River, is a 29-mile (47 km) long stream in Orange and Riverside Counties, draining a watershed of 133.9 square miles (347 km2). Its mainstem begins in the southern Santa Ana Mountains in the Cleveland National Forest. It winds west and south through San Juan Canyon, and is joined by Arroyo Trabuco as it passes through San Juan Capistrano. It flows into the Pacific Ocean at Doheny State Beach. San Juan Canyon provides a major part of the route for California State Route 74.
Aliso Creek is a 19.8-mile (31.9 km)-long, mostly urban stream in south Orange County, California. Originating in the Cleveland National Forest in the Santa Ana Mountains, it flows generally southwest and empties into the Pacific Ocean at Laguna Beach. The creek's watershed drains 34.9 square miles (90 km2), and it is joined by seven main tributaries. As of 2018, the watershed had a population of 144,000 divided among seven incorporated cities.
Oso Creek is an approximately 13.5-mile (21.7 km) tributary of Arroyo Trabuco in southern Orange County in the U.S. state of California. Draining about 20 square miles (52 km2) in a region north of the San Joaquin Hills and south of the Santa Ana Mountains, the creek is Trabuco Creek's largest tributary, and is part of the San Juan Creek drainage basin. Beginning in the foothills of the Santa Ana Mountains near the city of Mission Viejo, the creek is dammed twice to form Upper Oso Reservoir and Lake Mission Viejo. The creek is channelized and polluted along much of its length.
Arroyo Trabuco is a 22-mile (35 km)-long stream in coastal southern California in the United States. Rising in a rugged canyon in the Santa Ana Mountains of Orange County, the creek flows west and southwest before emptying into San Juan Creek in the city of San Juan Capistrano. Arroyo Trabuco's watershed drains 54 square miles (140 km2) of hilly, semi-arid land and lies mostly in Orange County, with a small portion extending northward into Riverside County. The lower section of the creek flows through three incorporated cities and is moderately polluted by urban and agricultural runoff.
Salt Creek is a small coastal stream in southern Orange County in the U.S. state of California. The 4-mile (6.4 km) creek drains 6.1 square miles (16 km2) in parts of the cities of Laguna Niguel, Dana Point, and San Juan Capistrano. The mostly channelized creek has no named surface tributaries. The creek begins in the central portion of the city of Laguna Niguel and flows west and south through a narrow canyon referred to as the Salt Creek Corridor, which is mostly inside a long and narrow regional park. It then flows into the Monarch Beach Golf Course in the city of Dana Point and enters a subsurface storm channel which carries it to its discharge point at Salt Creek County Beach.
Santiago Creek is a major watercourse in Orange County in the U.S. state of California. About 34 miles (55 km) long, it drains most of the northern Santa Ana Mountains and is a tributary to the Santa Ana River. It is one of the longest watercourses entirely within the county. The creek shares its name with Santiago Peak, at 5,687 ft (1,733 m) the highest point in Orange County, on whose slopes its headwaters rise.
Sulphur Creek is a 4.5-mile (7.2 km) tributary of Aliso Creek in Orange County in the U.S. state of California. The creek drains about 6 square miles (16 km2) of residential communities and parks in the southern San Joaquin Hills.
Bell Canyon is a major drainage of the Santa Ana Mountains in Orange County, California in the United States. Bell Creek flows about 14.4 miles (23.2 km) in a southerly direction to its confluence with San Juan Creek. The Bell Canyon drainage is located to the east and parallel to Cañada Gobernadora, and to the south of Trabuco Creek. After Trabuco Creek, it is the second largest tributary of San Juan Creek in terms of length and its watershed area of 26 square miles (67 km2).
San Mateo Creek is a stream in Southern California in the United States, whose watershed mostly straddles the border of Orange and San Diego Counties. It is about 22 miles (35 km) long, flowing in a generally southwesterly direction. Draining a broad valley bounded by the Santa Ana Mountains and Santa Margarita Mountains, San Mateo Creek is notable for being one of the last unchannelized streams in Southern California.
O'Neil Regional Park is a major regional park and greenway in eastern Orange County, California, United States, located along Trabuco Creek and Live Oak Canyon. The park encompasses 4,500 acres (1,800 ha) of canyon and riparian zone habitat, and includes campgrounds and trails for hiking, biking and horseback riding. The park was first established in 1948 when the owners of the O'Neill Ranch donated 278 acres (113 ha) of land for recreation purposes. Numerous land acquisitions between 1948 and 1982 brought the park to its present size. Many flora and fauna can be sighted, such as poison oak, bobcats and mountain lions, which are very rare.
Calero Reservoir, also called Calero Lake, is a reservoir in San Jose, California, located in the Calero neighborhood of Almaden Valley in South San Jose. It is the site of Calero County Park, which also includes a large area covering the lake and hundreds of acres of hills around it.
Alamitos Creek or Los Alamitos Creek is a 7.7-mile-long (12.4 km) creek in San Jose, California, which becomes the Guadalupe River when it exits Lake Almaden and joins Guadalupe Creek. Los Alamitos Creek is located in Almaden Valley and originates from the Los Capitancillos Ridge in the Santa Cruz Mountains, near New Almaden. This creek flows through the Valley's Guadalupe Watershed, which is owned by the Santa Clara Valley Water District. The creek flows in a generally northwesterly direction after rounding the Los Capitancillos Ridge and the town of New Almaden, in the southwest corner, before ambling along the Santa Teresa Hills on northeast side of the Almaden Valley. Its environment has some relatively undisturbed areas and considerable lengths of suburban residential character. Originally called Arroyo de los Alamitos, the creek's name is derived from "little poplar", "alamo" being the Spanish word for "poplar" or "cottonwood".
Trabuco Peak is a 4,607-foot (1,404 m) summit in the Santa Ana Mountains on the border of Orange and Riverside Counties, California, about halfway between Rancho Santa Margarita and Lake Elsinore. The mountain sits on the divide between Arroyo Trabuco on the west and the Temescal Creek valley on the east. Situated in the Cleveland National Forest, it is the highest summit in the Santa Anas south of Santiago Peak.
Arroyo Grande Creek is a major stream in San Luis Obispo County on the Central Coast of California. The creek flows 22 miles (35 km) in a southwesterly direction, from the Santa Lucia Range to the Pacific Ocean. It is a major source of water supply for southern San Luis Obispo County.
