A flea has tested positive for the plague in the Sierra Nevada, according to the California Department of Public Health.
The flea was found on a Yellow pine chipmunk during routine plague surveillance at Fallen Leaf Campground in South Lake Tahoe last month.
Plague is an infectious bacterial disease spread by squirrels, chipmunks and other rodents and their fleas.
People can get plague if they are bitten by an infected flea or come in close contact with an infected rodent or pet.
The last reported human cases of plague in California occurred in 2015 after two people were exposed to infected rodents in Yosemite Valley.