[2][3] Precipitation runoff from the mountain drains to Knik Arm via Raven Creek and the Eagle River.

Topographic relief is significant as the summit rises approximately 4,685 feet (1,428 m) above Raven Creek in two miles (3.2 km).

The mountain's toponym has not been officially adopted by the U.S. Board on Geographic Names.

Based on the Köppen climate classification, Rook Mountain is located in a tundra climate zone with long, cold, snowy winters, and cool summers.

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