I think I saw this in the Superior National Forest in the eighties or nineties. Anyone kn ow what the D1F1 means?
If it pertains to the US Forest Service, could be something to do with their regional structure. This may help you figure that out. https://www.fs.usda.gov/about-agency/organization Debora
WOW! Didn't expect that, FS is usually Forest Service like Deborah stated. Drilled hole to put on Key chain or used for dog tag type purpose.
Maybe @The Nailhunter knows something about these? Maybe something like these? https://www.antiquers.com/media/united-states-forestry-date-nails.7519/
Check this out @terry5732 : https://tinyurl.com/yxg7tfar Sounds like they don't entirely know what they have...
Well, at least it IS a description!! Gotta start somewhere, right? If you ask about it then ANY help is better than nothing!
Asked my son about the tag.....he has worked as a Field Botanist at a number of National parks. "One side looks like maybe grid coordinates. Could be a tag for a research plot. If so, bad that it is moved as people sometimes try to replicate historic studies to see how things have changed".
I have not seen that particular item before. But it is intriguing....I have seen similar items, my best guess is a "Tool Check", an item that was used to regulate who checked out a tool before the age of Bar Codes. I will ask a couple of friends and see if they have any ideas. Tags found in poles do not have the raised edge that circles the piece.