Willow Creek (formerly, China Flat) is a census-designated place (CDP) in Humboldt County, California, United States. The population was 1,710 at the 2010 census, down from 1,743 at the 2000 census. Willow Creek sits along the Trinity River. Residents of this small mountain town are commonly referred to as "Willow Creekers". It is the Bigfoot capital of the world, and holds an annual festival in honor of the creature.