Mentasta Lake (Mendaesde[2] in Ahtna Athabascan) is a census-designated place (CDP) in Copper River Census Area, Alaska, United States.

The racial makeup of the CDP was 28.87% White, 62.68% Native American, and 8.45% from two or more races.

Mentasta Lake is part of the Alaska Gateway School District.

Mentasta Lake Katie John School, a K-12 campus, serves community students.

The late subsistence hunting and fishing rights activist Katie John of Mentasta, who died at 97 on 5/31/13, helped develop an Ahtna language alphabet in the 1970s,[7] and has recorded a pronunciation guide of the Mentasta Dialect.