Mineral resources of the Rock River Canyon Wilderness Study Area, Alger County, Michigan

A mineral resource evaluation of the Rock River Canyon Wilderness Study Area, Alger County, Mich., was completed in 1975 by personnel of the U.S. Geological Survey and the U.S. Bureau of Mines. The area consists of approximately 22 km² in the Hiawatha National Forest.

Rocks exposed in the area include sandstone, shaly sandstone, dolomitic sandstone, sandy dolomite, and a minor amount of conglomerate; these rocks range in age from possibly Precambrian to early Middle Ordovician. A minor amount of unconsolidated glacier-transported debris was deposited during Pleistocene time.

No deposits of either metallic or nonmetallic minerals were found. Although resources of stone, sand, and gravel exist in the study area, they are considered to have small economic potential; similar materials are readily available and easily accessible in the surrounding region.