Madine Lake is 3,10 miles long (5 km) and 0,30 to 1,55 miles wide (500 m to 2.4 km). Its depth varies from 8 to 46 ft (2,4 to 14 m). Two islands stand amid its 2,718 acres (1,100 ha). They are not accessible to the public and serve as natural reserves for the fauna and flora. Green Island is the smallest (37 acres / 15 ha) and is north of the lake. Bois Gérard Island, which extends in the center of the water, is almost three times as large (98 acres / 40 ha). Around 80 sheep graze on its grounds from spring to early fall.