Saguaro Arrowhead
Paul found this grey arrowhead in one of Saguaro's ubiquitous dry washes. Out there in the flats of the Sonoran Desert, the landscape can all start to look the same. So he carried it with him for a little while, to show his coworkers, but soon thereafter felt like he should put it back before he forgot where it came from.
I went with him on his journey to return the artifact. But we couldn't find his spot; he just kept taking corners into different washes, slushing through thick sand just to determine that no, this wasn't it.
Finally, he found a spot that seemed like a good home for the arrowhead. If it had been shot with a bow, that happened sometime at least a hundred and fifty years prior, unless it had somehow been dropped, lost, or forgotten forever before that happened, but that was hard to believe. Paul knelt down and placed the little chiseled rock out of sight and the sunshine, away from other people's footprints, hoping nobody would disturb it for another hundred years or so.
When we stood up to leave, an owl was staring at us, even though this wasn't nighttime; it was the middle of the day. The owl watched us though, wide-eye contact. So we tried to explain ourselves. We showed the owl where we'd put the arrowhead, told him we were just returning it, thanked him for watching it. Then we walked back to our worksite.
Paul said that he tried to visit that arrowhead one more time, but he couldn't find his way back to where he'd left it.