USGS elevation data available through The National Map was converted to Cloud Optimized Geotiff (COG - GeoTIFF) format in mid-December, 2019. This change was made to improve product processing time, storage, and to support new and evolving cloud processing capabilities.
GeoTIFF is a widely supported raster format and is directly useable by most commercial software that reads or processes Digital Elevation Model (DEM) data. GeoTIFF DEMs will fit seamlessly into most workflows.
Instructions and translator scripts for converting from GeoTIFF to FLT format (Gridfloat) and for converting GeoTIFF to IMG format can be found on the Raster Conversion page.
For additional questions, please send an email to our National Map Help Desk: firstname.lastname@example.org.