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:

Abingdon
Ackley
Ackley NE
Adair N
Adair S
Adams
Adel
Adel NW
Adrian SW
Afton
Agency
Ainsworth
Akron, IA
Akron, MO
Albaton
Albert City
Albia
Alcester NE
Alcester NW
Alcester SE
Alexander
Algona
Allerton
Allison
Alloway Creek
Alpha
Alta
Alton
Altoona
Alvord
Amana
Ames E
Ames NW
Ames W
Amish
Anamosa
Anamosa NE
Andalusia
Andover
Andrew
Anita
Anita SW
Anson
Aplington
Arbor Hill
Arcadia
Argyle
Arispe
Arlington
Armstrong
Armstrong SE
Ash Creek
Ashton
Atalissa
Atlantic
Atlantic SW
Attica
Audubon
Aurelia
Aureola
Avery
Avoca
Avoca NW
Avoca SE
Ayrshire
Azen