+1 with pipedreamin and the rest! THANK YOU for posting this link and article!! I thought it was absolutely fascinating!! When I was a boy(living in SLC UT), we used to go out to near the Dugway Proving Grounds (don't know if that's the same or near the place in the article... most go back and read carefully) and search for geodes! Walk along the road, maybe 15 to 20 yards off, and find them... just laying there on top! Now, over 50 years later, I still have a big beauty geode sitting on the mantel piece. I seem to recall, the odd nat-am artifact would show up... never thought they could be 12,000 year old ice agers!! How exciting!!