The Ancient Murrelet is a year-round resident of the Aleutian Islands, Gulf of Alaska, and islands off of the coast of central British Columbia (Sibley 2014). This species winters off of the Pacific coast throughout its breeding range south to central California (Gaston and Shoji 2010). In Montana, the Ancient Murrelet has several historic records but only two over the last decade (Montana Bird Distribution Committee 2012).
For a comprehensive review of the conservation status, habitat use, and ecology of this and other Montana bird species, please see Marks et al. 2016, Birds of Montana.