The state name has been omitted when it is a single state only but given when it is two or more. Quads showing territory in two states of the six are listed in the inventory of the state named first on the quad. This column keeps the different editions in chronological order and is a condensed version of all the various kinds of revision that a topo quad may have. The USGS code for the 7 quads, based on 1-degree blocks of latitude and longitude plus an alphanumeric for each quad, is given. ISL does not use these quad numbers for filing or retrieving, but the map index does.
Secondary organization is alphabetically by the name of the quad.
The several date columns in the 7 lists have been reduced to one date column, in chronological order with latest first. The index column merely indicates whether or not the quad has been marked off on the oldest index map the State Library owns for that state.