Blocksburg (formerly, Blocksburgh, Blockburger's and Powellville) is an unincorporated community in Humboldt County, California. It is located 15 miles (24 km) east-southeat of Weott, at an elevation of 1594 feet (486 m).
The ZIP Code is 95514.The Blocksburgh post office opened in 1877, the name was changed to Blocksburg in 1893. The name is for Benjamin Blockburger, local merchant. The name was originally Powellville in honor of Joseph James Powell, the first settler.