Abstract:
Digital Elevation Models are useful for deriving elevations;
modeling 3D surfaces; creating derived products such as
slope, aspect, and relief layers; creating watersheds and
conducting watershed analyses; and conducting other types of
terrain analyses.
Digital Elevation Model (DEM) is the terminology adopted by
the USGS to describe terrain elevation data sets in a digital
raster form. The
... 7.5-minute DEM (30- by 30-m cell size, in a
Universal Transverse Mercator (UTM) projection) provides
coverage in 7.5- by 7.5-minute blocks. Each product provides
the same coverage as a standard USGS 7.5-minute quadrangle
without over edge. The DEM data are stored as a series of
profiles in which the spacing of the elevations along and
between each profile is in regular whole number intervals.The
Yellowstone National Park 30 m DEM was compiled from a
combination of of Level I and II USGS 30 m DEMs, elevation
values range from 1528 to 4186, describing 1528 - 4186
meters.
The parkwide DEM was compiled by Lisa Landenburger,
Geographic Information and Analysis Center (GIAC), Montana
State University, Bozeman, MT. This data set is unpublished.
material.
This summary was abstracted from the FGDC metadata file. 
