The valley contains a series of neighborhoods, comprising the largest populated place within the corporate limits of the City and Borough of Juneau, Alaska's capital.
The valley was formed by Mendenhall Glacier over the course of roughly three thousand years.
It was named for the American physicist and meteorologist Thomas Corwin Mendenhall.
The Mendenhall Valley begins ten miles from the downtown area, at the intersection of Egan Drive and Glacier Highway, and ends ten miles farther west at the intersection of Glacier Highway and Mendenhall Loop Road at Auke Bay.
The Valley forms the core of Alaska's 34th election (or state House) district, which is represented in the Alaska House of Representatives by Andi Story, a Democrat.