The wilderness is named for its high steep walls that narrow in the lower section so that they block the light in the morning and late afternoon.

Dark Canyon continues west within a U.S. Bureau of Land Management primitive area that is recommended for wilderness designation.

Life zones range from ponderosa pine and aspen-covered high country to desert vegetation in the bottom of Dark Canyon.

Wildlife species include mule deer, some mountain lions, black bear and bighorn sheep.

The Forest Service once recommended closing the area to vehicles but this corridor was kept open as a compromise in the Utah Wilderness Act of 1984.