It is heavily glaciated and is made primarily of high alumina basalt and andesite.

The southern flank of the mountain is assumed to be its youngest side.

[1] In comparison to other Aleutian stratovolcanoes, Moffett is a small vent, characteristic of its mixed composition.

It was named by the U.S. Navy in 1936 for Rear Admiral William Adger Moffett.

[3] It has occasionally been skied with there once being a ski-lift on the lower portion.