ESRI ArcInfo Grid

ESRI ArcInfo Grid (or ESRI Grid, ArcGrid; "ArcInfo" may also be spelled Arc/Info) is a geospatial raster/grid format from ESRI. There is a binary version (ADF), and an "ASCII" version of the format.

Identification
An ADF "file" is actually a directory containing multiple files (most with an .adf extension) that don't all use the same format. Some of the files start with bytes.

Specifications

 * About the ESRI Grid format
 * Arc/Info Binary Grid Format (Archived)
 * ESRI ASCII Raster format

Sample files

 * https://walrus.wr.usgs.gov/swces/inlets/criver/coverages/ ...

Links

 * Esri grid
 * Esri website