I can't figure it out, unless it has to do with a Jurisdictional thing between BLM and USFS most of the Eastern lands were purchased after 1900 . I responded to a similar question here in an earlier post where the poster questioned why there are not more GPAA claims/places to dig in the east given the extent of National forest land, and pretty much got told to go to hell by a gentleman from Montana for my opinion that the poster asked a relevant question. I guess my membership dues are good as long as it keeps him dredging...oh well pay it forward I say LOL.

I just asked this question at my local Weekend Gold Prospectors club meeting and was told:
The 13 original colonies already had their laws and land grants in place concerning the
treatment of mining claims, processes and procedures by the time the Louisiana Purchase
and the Spanish American War had occurred.
The new territories needed some incentives and processes in place to make exploration of the new territories profitable.
So, the Mining Laws were enacted around 1870 (Mining Law of 1872 )to protect the endeavors of the early explorers and miners
and companies that developed those mining claims on public lands.
The Mining Districts were part of the Mining Law of 1870-72 and were the agencies the law created to deal with
mining claims issues before they went to any other legal or regulatory agency.

Congress seems to think that all miners are "stealing" these natural resources from the U.S. Government under the protection of the
Mining Law of 1870-72. There have been several modifications to that act.
The 1981 Federal Land Protection and Management Act (FLPMA) really put some big nails in the Mining Act.
There have been some more attempts to remove those protections in the 2007 and 2009 Hard Rock Mining and Reclaimation Acts.

Man, all I want to do is dig some dirt and clean it. What is wrong with that?
Just like a politician to make playing in the dirt and water a crime !!