[2] The mountain is situated 44 km (27 mi) west of Haines Junction, 18 km (11 mi) southeast of Kluane Lake, and can be seen from the Alaska Highway midway between the two.

Its nearest higher peak is Mount Maxwell, 27.7 km (17.2 mi) to the southwest.

He was related to noted geologist DeLorme Donaldson Cairnes (1879–1917), for whom this mountain is named.

[4] Based on the Köppen climate classification, Mount Cairnes is located in a subarctic climate with long, cold, snowy winters, and mild summers.

Precipitation runoff from the peak and meltwater from its pocket glaciers drains into tributaries of the Kaskawulsh River.