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 town of Arcata near [California Redwood Coast-Humboldt County Airport] in McKinleyville. The river's headwaters are in the Coast Range near South Kelsey Ridge.
The Mad River about 4 miles (6.4 km) above the mouth
Humboldt County, California
Humboldt County is a county located in the U.S. state of California. As of the 2020 census, the population was 136,463. The county seat is Eureka.
Aerial view of Humboldt Bay
Mouth of Humboldt County's Little River on the Pacific Coast
Rockefeller Forest, the largest remaining old-growth Redwood forest on earth, is located within Humboldt Redwoods State Park.
The Lanphere Dunes, a protected coastal environment