Photorevised maps have not been field checked. Orthophotomaps are multicolor photographic-image maps in standard quadrangle format with added topographic detail. Orthophotoquads are monocolor or multicolor photographic-image maps in standard quadrangle format without topographic detail. Most monocolor orthophotoquads are not being published but are available in the form of diazo or photographic prints. The Index to Orthophotoquad Mapping showing information about available published and unpublished orthophotoquads is free on request from the distribution centers listed with the ordering forms and information.
Some counties require more than one map.
Level of content may vary between States, and State sales indexes should be consulted for a more detailed description of each map. Most of these maps are not being published but are available in other forms. Copies of the drawings which comprise these maps are available either as a composite of all features or separately by feature. Discount rates and ordering instructions are given with the ordering forms and information. State topographic indexes and catalogs are free on request.