The lake is a 9 miles (14 km) long, narrow, natural creation, resulting from continental collision and glacial scouring.

A dam originally built in the town of Oakland in 1905 increased the lake's size.

In the first part of the 20th century, Messalonskee Stream provided waterpower for Oakland's Cascade Woolen Mill, as well as for a number of factories responsible for Oakland's long-defunct title as "axehead capital of the world."

Messalonskee Lake is home to a great variety of wildlife, including great blue herons, bass, yellow perch, white perch, sunfish, painted and snapping turtles, loons, and occasionally Bald Eagles can be seen soaring above the lake.

The surrounding community has recently formed the Messalonskee Lake Association in the interest of its protection and preservation.