The Yellow-bellied Flycatcher has often been confused for other species, overlooked, or otherwise ignored, and, as such, the historical record may not be completely trusted regarding the frequency and abundance of the species’ occurrence in Massachusetts over time. Spencer Fullerton Baird, later to become secretary of the Smithsonian Institution, collected the first specimen in 1840 in Pennsylvania, passing it on to John James Audubon for documentation (Audubon 1844). Charles Johnson Maynard reported shooting one on May 31, 1869, and then eight more the next day (Studer 1876), and from then on the species became known as a rare to uncommon migrant in the state. William Brewster saw a pair of Yellow-bellied Flycatchers on Mount Greylock on June 28, 1883, the first suspicion of possible breeding activity within the state (Faxon 1889), but for most of the twentieth century, the bird remained a Massachusetts mystery. Yellow-bellied Flycatchers maintained this mysterious breeding status in the Commonwealth throughout the years of the Atlas 1 fieldwork. Two Possible blocks located in the Berkshire Highlands region, both containing high-altitude bogs of the sort the species is known to favor, reported the presence of Yellow-bellied Flycatchers during the breeding season. While Yellow-bellied Flycatchers continued to evade Confirmation through Atlas 2, their ongoing presence in the western part of the state was tantalizing. A Probable report from a Berkshire Highlands block that had Possible Yellow-bellied Flycatchers during the first Atlas clearly represented a site worthy of search during the subsequent summer. The presence of Yellow-bellied Flycatchers on Mount Greylock, where Brewster made his sighting almost a century and a half ago, underscores the species’ status as a very local and possibly rare summer resident in the higher elevations of Berkshire County.