Eureka is the principal city and county seat of Humboldt County in the Redwood Empire region of California. The city is located on U.S. Route 101 on the shores of Humboldt Bay, 430 km north of San Francisco and 160 km south of the Oregon border.
Eureka is the largest coastal city between San Francisco and Portland, Oregon. It is one of California's major commercial fishing ports. It was historically an important place in the lumber trade. Humboldt Bay is the second largest bay in California.