Mad River (California)

Mad River
River
Mad River about 15 miles (24 km) above the mouth
Country	United States
State	California
Counties	Humboldt, Trinity
Tributaries
- left	South Fork Mad River, Blue Slide Creek, Littlefield Creek
- right	Barry Creek, Pilot Creek, Bug Creek, Graham Creek, Boulder Creek, Maple Creek, Canõn Creek, North Fork Mad River, Lindsay Creek, Mill Creek
City	Arcata
Source
- location	California Coast Ranges
- elevation	4,845 ft (1,477 m)
- coordinates	40°12′20″N 123°9′23″W / 40.20556°N 123.15639°W / 40.20556; -123.15639
Mouth	Pacific Ocean
- elevation	0 ft (0 m)
- coordinates	40°56′31″N 124°8′6″W / 40.94194°N 124.13500°W / 40.94194; -124.13500Coordinates: 40°56′31″N 124°8′6″W / 40.94194°N 124.13500°W / 40.94194; -124.13500
Length	113 mi (182 km)
Basin	497 sq mi (1,287 km2)
Discharge	for near Arcata
- average	1,573 cu ft/s (44.5 m3/s)
- max	81,000 cu ft/s (2,293.7 m3/s)
- min	17 cu ft/s (0.5 m3/s)
Map of the Mad River watershed

The Mad River is a river in upper Northern California. It flows for 113 miles (182 km) in a roughly northwest direction through Trinity County and then Humboldt County, draining a 497-square-mile (1,290 km²) watershed into the Pacific Ocean north of the college town of Arcata near Arcata-Eureka Airport in McKinleyville. The river's headwaters are in the Coast Range near South Kelsey Ridge.

Before Euro-American settlers arrived in the mid-1800s, the native peoples occupying the lower Mad River watershed were the Wiyot (from approximately Blue Lake to its mouth, plus the greater Humboldt Bay region) who spoke a dialect affiliated with the Algonquian language family, with upriver reaches controlled by three different groups whose languages are related to the Athabascan family, the Whilkut, Nongatl and Lassik (Baumhoff 1958). Today, among these distinct groups, only the Wiyot-affiliated Blue Lake Rancheria is a federally recognized tribe and holds lands in trust for its citizens. The Whilkut, Nongatl and Lassik were essentially annihilated during the Bald Hills War in the 1860s. The river was named in December, 1849 in memory of an incident when Dr. Josiah Gregg lost his temper when his exploration party did not wait for him at the river mouth.

The Mad River drains approximately 497 square miles (1,290 km²) of the Coast Range Geomorphic Province and empties into the Pacific Ocean north of Humboldt Bay in Humboldt County, California. The basin is about 100 miles (160 km) in length and averages six miles (10 km) wide. Elevations range from sea level at the mouth to 3,000 feet (910 m) along the western ridge to 6,000 feet (1,800 m) in the headwaters. Principal tributaries to the Mad River include South Fork Mad River, North Fork Mad River, Barry Creek, Pilot Creek, Deer Creek, Bug Creek, Graham Creek, Grace Flat, Blue Slide Creek, Boulder Creek, Maple Creek, Canõn Creek, Lindsey Creek, and Mill (Hall) Creek.