Thirty-nine types of surficial geologic deposits and residualmaterials of Quaternary age are described and mapped in the greaterDenver area, in part of the Front Range, and in the piedmont andplains east of Denver, Boulder, and Castle Rock. Descriptionsappear in the pamphlet that accompanies the map. Landslidedeposits, colluvium, residuum, alluvium, and other deposits ormaterials are described in terms of predominant grain size, mineralor rock composition (e.g., gypsiferous, calcareous, granitic,andesitic), thickness of deposits, and other physicalcharacteristics. Origins and ages of the deposits and geologichazards related to them are noted. Many lines between geologicunits on our map were placed by generalizing contacts on publishedmaps. However, in 1997-1999 we mapped new boundaries, as well. Themap was projected to the UTM projection. This large map areaextends from the Continental Divide near Winter Park and Fairplay (on the west edge), eastward about 107 mi (172 km); and extends fromBoulder on the north edge to Woodland Park at the south edge (68mi; 109 km).