Oso Creek

Oso Creek
Oso Creek
Etymology	Spanish: "Bear Creek"; name origin unknown
Location
Country	USA
State	California
Region	Orange County, Riverside County
Physical characteristics
Source	Oso Creek Canyon, Santa Ana Mountains
• coordinates	33°40′31″N 117°36′28″W / 33.67528°N 117.60778°W / 33.67528; -117.60778
• elevation	1,287 ft (392 m)
Mouth	Trabuco Creek, San Juan Capistrano
• coordinates	33°31′10″N 117°40′19″W / 33.51944°N 117.67194°W / 33.51944; -117.67194
• elevation	161 ft (49 m)
Length	13.5 mi (21.7 km)
Basin size	20 sq mi (52 km2)
Discharge
• location	Trabuco Creek
• average	33 cu ft/s (0.93 m3/s)
• maximum	5,710 cu ft/s (162 m3/s)
Discharge
• location	Galivan Basin
• average	0 cu ft/s (0 m3/s)

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.^[1] 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.

"Oso", meaning bear in the Spanish language, was likely the name given to the creek by Spanish conquistadors. Up to the 1970s, the Oso Creek watershed was mostly undeveloped and the creek ephemeral. The watershed lies close to two major wilderness areas - Aliso and Wood Canyons Wilderness Park to the southwest and O'Neill Regional Park to the west, on Trabuco Creek - but has no major parks within its boundaries. Interstate 5 parallels the creek for over half of its length.