Few state mammal records are as tightly pinned to one place as this one. Craters of the Moon National Monument holds about half of Idaho’s 110 crater chipmunk reports since 2000, and Butte County, which contains the monument, accounts for 47 on its own. The chipmunk takes its name from those black lava fields, and the record says the name fits: beyond the monument, reports scatter thinly through Custer (16), Ada (11), and Boise (10) counties, with small clusters reaching the Sawtooth and Yankee Fork country.
Every one of these records comes from iNaturalist, which matters for interpretation. A chipmunk living on photogenic, heavily visited lava flows will look far better documented than one in quiet sagebrush, so the monument’s dominance is partly a measure of foot traffic. Reports peak in July and August, the height of both chipmunk activity and tourist season. This is a species only recently recognized as its own, with no NatureServe rank yet, so each confirmed record away from Craters of the Moon genuinely extends what’s known about its range.
