Mount Mary is located seven miles (11 km) east of Seward in the Kenai Mountains, on land managed by Chugach National Forest.

Precipitation runoff and glacial meltwater from the mountain drains west to Resurrection Bay via Fourth of July Creek.

Although modest in elevation, topographic relief is significant as the summit rises 3,800 feet (1,158 m) above the creek in 1.65 miles (2.66 km).

The mountain's toponym was officially adopted June 13, 2019, by the United States Board on Geographic Names.

[4] Weather systems coming off the Gulf of Alaska are forced upwards by the Kenai Mountains (orographic lift), causing heavy precipitation in the form of rainfall and snowfall.