Cliff Mountain stands within the watershed of the Opalescent River, a tributary of the Hudson River, which in turn drains into New York Bay.

The southeast side drains into Upper Twin Brook, thence into the Opalescent River.

According to the 1897 survey of the Adirondacks, the height of Cliff Mountain was over 4,000 feet (1,219 m), so it was included in the 46 High Peaks; the 1953 USGS survey found it and three other peaks to be lower, but the list has not been changed.

The mountain is within the High Peaks Wilderness Area of Adirondack State Park.

This article about a location in Essex County, New York is a stub.