Mark,
Up there in your dad’s neck of the woods that could have been one of Kit Carson or Lucian Maxwell’s rifle balls!!!!
😉
I was thinking a Ft Union soldier - but you may be right! (Ain't that far from Rayado, as the mountain man travels).
Funny you mention Ft. Union. If they had any company riflemen there that were issued M1841 "American Yagers", the arsenal issue cartridges for that rifle had the patch hand sewed around a .54 calibre round ball!!!
Just some useless trivia for the morning!