Humboldt County is located on the northwest coast of the U.S. state of California, on the Pacific Ocean. The county seat is Eureka. Humboldt County was formed in 1853 and derived its name from Humboldt Bay, that was named in honor of the great naturalist and world explorer, Baron Alexander von Humboldt. The county has a total area of 4,052 mi², 88% of it is land and 12% of it is water. As of the 2000 United States Census, there were 126,518 people and 51,238 households in Humboldt County, and the population density was 35/mi².