A review of numbers and distribution of Red Knots (Calidris canutus) on the Massachusetts coast during southward migration indicates major declines beginning in the early 1970s. Overall numbers increased during the third quarter of the 20th Century, largely at mainland versus Cape Cod locations, and then declined early in the fourth quarter at the mainland—but not the Cape Cod—locations. Evidence suggests that both the mainland and the Cape Cod areas were historically used by knots having Patagonian destinations, but that recently the Cape Cod locations have increasingly been used by knots with wintering destinations in the southeastern United States, thus balancing out the declining numbers of knots with Patagonian destinations.