Ice Mountain, along the North River near North River Mills, Hampshire County, has an extensive area of boulders and rock debris within which water freezes in the winter. The protective layer of rocks allows the ice to melt slowly through the spring and early summer. At the base of the slope, cool air emits from small vents among the rocks. In the past, the ice was reported to persist in some years until September, was used to make homemade ice cream, and was even used to cool a dairy for the summer storage of milk. Now, ice can generally be found only into June, although the cool air persists through most of the summer.

The cool conditions allow many northern plants, snails, and insects to live at Ice Mountain, despite a relatively low elevation. Among these plants are bunch berry, purple clematis, skunk currant, and nanny berry, which are typically found in West Virginia at elevations above 3,000 feet. Bristly rose and twin flower, plants of the far north, and the rare Appalachian oak fern also occur here. Away from the ice vents, the vegetation is typical for the region. The Nature Conservancy owns and manages Ice Mountain as a nature preserve. The elevation of Ice Mountain is 1,429 feet.

On May 18, 2012, Ice Mountain was named a National Natural Landmark by the U.S. Department of the Interior at a ceremony to mark the 50th anniversary of the program. National Natural Landmarks are selected for their outstanding condition, rarity, diversity, and value to science and education.