EXPLANATION OF MAP UNITS: Geologic map of the Talkeetna Mountains C-4 Quadrangle and adjoining areas, central Alaska (1:50,000 scale).

The article offers information on the symbols used in map units. Topics discussed include use of Qa to describe undifferentiated floodplain alluvial deposits, use of Trrp to show high silica rhyolite, use of Kg indicates granite rocks and, use of KJmf to show metamorphosed and interbedded sandstone in the area.