The areas are generally shallow depressions that have flat or irregular floors. Areas covered by water most of the year are mapped as Water. Some areas have a few hummocks or small dunes. Cinder land is composed of loose cinders and other scoriaceous magmatic ejecta. Water-holding capacity is very low, and trafficability is poor.
Cirque land consists of areas of rock and rubble in characteristically cirque shape.
The areas have been caused by glacial erosion. Dumps are areas of smoothed or uneven accumulations or piles of waste rock and general refuse. Dumps, mine consist of areas of waste rock from mines, quarries, and smelters. Some dumps with closely associated pits are mapped as Dumps-Pits complex. Dune land consists of sand in ridges and intervening troughs that shift with the wind.