The name Umbagog is properly pronounced with the stress on the second syllable (um-BAY-gog) and is said to come from the Abenaki word for "shallow water".

An interesting feature along its northwest shore is an expansive natural floating island composed of generations of decomposing marshland vegetation.

The area is abundant with wildlife, including coyote, wild turkey, bald eagle, osprey, bobcat, moose, rabbit, bear, loons and many other native species.

[3] The lake's area and depth were markedly increased with the construction of a dam at Errol in the 19th century.

The lake is classified as a warmwater fishery, with observed species including smallmouth bass, chain pickerel, horned pout, and northern pike.