William Poolman of Pacific Grove has been charged with one felony count of mailing a false weapon of mass destruction causing fear. He is scheduled to appear in court Friday.
The Department of State Parks and Recreation cited Poolman in February for failing to pay for parking at Carpinteria State Park.
Poolman unsuccessfully appealed the citation. He sent his payment to a parking citation collection agency in Orange County and included a gram of a white substance that turned out not to be hazardous.
Authorities say he also wrote threatening messages in the letter.