Data is available as TIFF and MrSid compressed versions.
TIFF format data is available only at the base tiling level - idxp7500 - defined by a rectangular grid of cells with x-y dimensions of 7500 feet.
Primary user data is provided at second tier tiling level - idxptrmbr. This tiling level references the PLSS township-range grid with tiles buffered to a minimum-bounding rectangle of the township. Imagery at this level is provided only as compressed (compression ratio = 7, near lossless) imagery in JPG2000 format.
Imagery is also available as larger area mosaics at the idxpzone level (if appropriate) and as a highly compressed entire area of interest mosaic. Both the zone and entire area mosaic, called key region, is provided only as MrSid images.