The mountains are the remnants of much higher peaks, composed of Precambrian rocks which have gone through successive periods of uplift and erosion.

Pleistocene glaciation deposited sandy loam or loamy sand glacial till on most of the terrain, and the soils, podzolized in well drained areas, are largely mapped as Munising or Keweenaw series.

No official weather records are maintained in the mountains, but annual snowfall averages easily exceed 200 inches (510 cm) across the entire range.

Fauna in the area includes wolves, moose, coyotes, cougar, fisher, marten, mink, white-tailed deer, gray and red foxes, porcupines, black bears, river otters and beavers.

[2] The Huron Mountain Wildlife Foundation sponsors natural science research in the region, including the HMC lands.