Someone will get pissy I linked these, but whatever. I use these 3 resources above all the others I know of. Great for checking land status, terrain, locations of mines, along with brief details of what to expect.
westernmininghistory.com can give you detailed history behind a mine but I rarely use it for anything other than satisfying my curiosity.
>https://thediggings.com/usa/map >http://publiclands.org/Get-Books-and-Maps.php?plicstate=OR >https://caltopo.com/map.html#ll=44.70664,-120.49204&z=14&b=mbt You can clearly see by the URLs I'm in Oregon and I'm too lazy to fix the links as this is what I have bookmarked