Thompson Lake is the largest lake in the Little Androscoggin watershed. The north end of the lake overflows into the Little Androscoggin River through the village of Oxford. The lake forms the boundary between
Otisfield to the west and Oxford and Poland to the northeast and southeast, respectively. The southern tip of the lake is in
Casco. Greeley Brook is the largest tributary to the lake, and flows from Sand Pond in
Norway. Smaller tributaries include Knights Brook and Jerry Brook in Otisfield and Potash Brook in Poland. The lake is good habitat for
smallmouth and
largemouth bass and has been stocked with
trout. ==See also==