The Indiana-based Public Interest Legal Foundation is demanding extensive voter registration information and other documents from Plumas County, or threatening to file suit.
The organization says Plumas County has 456 more registered voters than it does adult residents. Spokesman Logan Churchwell declined to say if his organization believed any vote was ever cast illegally, or if the outcome of any election was compromised.
Churchwell said the organization bases its claim on a mismatch between the number of registered voters and US Census estimates for 2016. The census figures derived from computer models extrapolated from the 2010 census.
The organization also includes 3,894 inactive voters, which could account for the discrepancy.
Plumas County Clerk-Recorder Kathy Williams said her office was surprised by the demand letter and its tone — and that officials had spent much of Tuesday considering a response.
Plumas County voters are declared “inactive,” once they skip two presidential elections. That means as many as 11 years could pass before a voter’s registration is voided.
Williams said that the county’s large number of seasonal residents may affect the accuracy of census figures. The county also typically has among the highest turnout rates in California, she said.
Demand letters were also sent to San Diego and 246 other counties across the nation.