According to the United States Census Bureau, the town has a total area of 48.7 square miles (126km2), of which 46.9 square miles (121km2) is land and 1.7 square miles (4.4km2), or 3.51%, is water. Thompson possesses many small ponds, such as Little Pond and Long Pond, as well as two principal lakes: West Thompson Lake and Quaddick Lake. Contained within its borders are several moderately sized rivers, the largest of which is the French River, a tributary of the Quinebaug River, which also runs through Thompson. The highest point in Thompson and the surrounding villages is Fort Hill at 649 feet (198m) above sea level. Thompson is a rural town in Windham County, Connecticut, United States. The town was named after Sir Robert Thompson, an English landholder. The population was 9,458 at the 2010 census. Thompson is located in the northeastern corner of the state and is bordered on the north by Webster, Massachusetts, on the east by Douglas, Massachusetts and Burrillville, Rhode Island, on the west by Woodstock, Connecticut, and on the south by Putnam, Connecticut.