Hoopa is an unincorporated community and census-designated place in Humboldt County, California. It is located 10 miles south of Weitchpec, at an elevation of 328 feet. The ZIP Code is 95546.Hoopa is a rural town located entirely on the reservation of the Hupa. The federal designation of the area is the Hoopa Valley Indian Reservation. Hoopa is on the Trinity River. Hoopa is in the area code of 530.The Hoopa Valley post office opened in 1861, the name was changed to Hoopa in 1895, to Hupa in 1900, and back to Hoopa in 1902.