Glucocorticoid metabolite (GCM) concentration measured in samples collected from sites across the western US during 2010–2012. Boxes depict medians and 25% and 75% quartiles. Whiskers extend through the 95% interquartile range. Sites are grouped according to either national park or designated eco‐region. Abbreviations (in alphabetical order) are as follows: CERO = Central Rockies, CRGO = Columbia River Gorge, CRLA = Crater Lake National Park, CRMO = Craters of the Moon National Monument and Preserve, GRSA = Great Sand Dunes National Park and Preserve, GRTE = Grand Teton National Park, LABE = Lava Beds National Monument, LAVO = Lassen Volcanic National Park, NOUT = Northern Utah, ROMO = Rocky Mountain National Park, YELL = Yellowstone National Park.