Each district has a file, and each county has a general file for things that cannot easily be included in a district file. It should be noted that Map 37 does not contain the nonmetal mining districts, and a few of the metal mining districts are also missing. Items that fall outside of a district may be either included in the nearest district or in the appropriate county general file. Report 47 is much more complete than Map 37 and is very useful in conjunction with this database. However, it does not use the numbering system of Map 37 or this database.
Many districts have more than one name.
These other names are cross referenced in Report 47. County General Files have an three-letter alphabetical designation usually consisting of the county name's first two letters and ending in G. ITEM is the number of the item listed in the district file. The items are numbered as they were received and entered, and all items on a particular mine or area in a particular district are not necessarily numbered consecutively. Item numbers preceded by an M indicate an item filed in the large map files. As noted before, most large maps have not been entered yet.