During a study of the relationships between forest snags and cavity-nesting birds in the northern Rocky Mountains, I observed the effectiveness of the Brown Creeper’s (Certhia familiaris) cryptic color pattern and behavioral response. The combination made the bird nearly undetectable near its nest site on an Engelmann Spruce (Picea engelmannii) snag. The nest tree was located on the Coram Experimental Forest, Flathead National Forest, northwestern Montana, at an elevation of 5350 feet.