Do you think you would like to be the CO for a Historic Caches challenge cache in your county? To qualify, you must qualify to find such a cache. In other words, you must have already found five of the seven oldest caches in that county and be willing to keep the list of available seven caches up to date.
The following counties do not yet have Historic Caches in this series:
Alger, Baraga, Dickinson, Houghton, Iron, Keweenaw, Luce, Marquette, Schoolcraft.