Surveys and banding records of Calidris canutus rufa indicate that Red Knots migrate mainly north and south through Massachusetts, Delaware Bay, and Virginia, and winter in Florida and South America. We fitted 40 adult Red Knots with geolocators at Monomoy National Wildlife Refuge, Massachusetts, during fall migration (2009), and in this paper report on the locations of migration and wintering along the Atlantic coast of the United States of eight recaptured knots. The knots' migration patterns varied: four birds wintered along the U.S. Atlantic coast, and the rest went to the Caribbean islands or the northern edge of South America. Knots spent 58 to 75 days in Monomoy Refuge before migrating south in November. Seven of the eight stopped along the U.S. Atlantic coast for relatively long periods. For the six with complete yearly cycles, the total time spent along the Atlantic coast averaged 218 days (range 121–269 days). All eight knots crossed the Atlantic outer continental shelf from two to six times. Areas of use were Monomoy, Long Island, New Jersey, Maryland, the Outer Banks of North Carolina, South Carolina, and Florida. These data indicate that Red Knots moving through Massachusetts in the fall had variable migration patterns, spent considerable periods of their life cycle along the Atlantic coast, and each knot followed a separate and distinct path, which suggests that knots can be at risk along the Atlantic coast for a substantial period of their life cycle.