Digital Elevation Models (DEM) are digitized versions of USGS's 7.5 degree topographic maps. With the help of additional software, they may be used to automatically define the base elevations for objects included in air dispersion modeling analyses. These DEM files can be downloaded from this website below. All DEM files on this site are listed based on the letter they begin with and are named based on the USGS quadrangle they represent.

Choose the letter with which the name of the quadrangle begins:

Choose the DEM file you wish to download:

Dallas Center
Dallas City
Danbury
Danville
Davenport E
Davenport W
Davis City
Dawson
De Soto
Decorah
Dedham
Deep River
Defiance
Delmar N
Delmar S
Delta
Denison
Denison SW
Denver
Depew
Derby
Des Moines SE
Des Moines NE
Des Moines NW
Des Moines SW
Dewey
DeWitt
Diagonal
Dickens
Dike
Dixon
Dolliver
Donahue
Donnellson
Doon
Dorchester
Douds
Dougherty
Dow City
Dows E
Dows W
Dubuque N
Dubuque S
Dumont N
Dumont S
Duncan
Duncombe
Dundee
Dunkerton
Dunlap
Dunlap NE
Dunlap NW
Dunlap SW
Dunnell
Durant
Dyersville E
Dyersville W
Dysart