----------------------------Original message---------------------------- Howdy: Here at U of U, I'll soon have two projects going in the Map Collection: a major stack shift; and retrospective conversion of topo sheets, including reclassing the different series which have historically lodged together with the 7.5-minute quads. I'm trying to plan for the space needed for these series. Does anyone have statistics on the volume of sheets produced in the obsolete series? These are: 30-minute maps at scale 1:125,000; 60-minute maps at scale 1:250,000; 1:31,680-scale maps; 6-minute (scale 1:24,000); and 15-minute (scale 1:48,000); And do I understand correctly that the 60-minute maps were confined to the western states, while the 30-minute ones were primarily eastern states? Thanks... Ken Rockwell