In 2024, the fungus that causes white-nose syndrome in bats was detected in several counties across California, although bats with visible signs of the disease have yet to be observed in the state. White-nose syndrome has killed millions of bats since it was first detected in New York in 2006. Hibernating bats like little brown myotis, Yuma myotis, and cave myotis are especially vulnerable to the disease. White-nose syndrome develops when the fungus Pseudogymnoascus destructans invades bat skin cells, damaging delicate wing tissue. Bats with white-nose syndrome end hibernation early when water and insect prey resources are scarce, which often results in dehydration and depletion of fat reserves. As a result, infected bats often perish. In 2023, the California Department of Fish and Wildlife first confirmed presence of the fungus in a bat roost in Humboldt County. In 2024, the fungus was also confirmed present in Sutter, Placer, Amador, and Inyo counties. Inconclusive laboratory results suggest the fungus may also be present in several other counties. Presence of the fungal pathogen suggests the disease could manifest in California’s hibernating bats within the next few years. Sustained efforts to monitor bat populations will be critical to understanding and managing this devastating disease.