Sorry, no fossilized trees in the Black Hills. All that stuff eroded away millions of years ago. However there are many fosillized trees in the Badlands (think of the landscape shots in the movie Starship Troopers filmed here in the Badlands).
Nothing near 5 ft across, much less a hundred.
And yeah, really nice surprise. JonW makes a first rate bow even when he has a second rate piece of osage to work with!
Once again I am deeply impressed with the quality of the people that share this forum. Granted, there has been a rash of bows sent to unsuspecting recipients lately, but this is not all that unusual for these folks. The generosity in sharing knowledge is equaled with how people here share their resulting craftsmanship. I am honored with Jon's bow. Again, thanks JonW!