Hunting for Archeology around Boulder CO, Day 1 - The Pawnee Grasslands

When else was I going to get anything like a genuine "Great Plains" experience?. Planning to visit my son in Boulder I spent weeks pouring over maps and aerial photos trying to decide where we should go look for arrowheads. 

Found the perfect spot: next to a major creek (Howard Creek), on public land (Pawnee Grasslands National Park), and signs of past plowing - with long straight lines from industrial scale plowing overlaid on curved lines from manual plowing. So the ground will have been churned. I zoomed in on a destination (up CR77 from Briggsdale, between CR96 and CR100 - figured we could pretend to be bird watching, if deception was called for) and, to my delight, spotted a marking on the map: "Arrowhead Windmill". Seemed just right.

Drove out that way (~100 miles from Boulder), getting to chat with my son, we finally arrived and stepped out. The ground was covered with chips:

Mostly chalcedony (a form of SiO2, different from quartz in its flaking properties) and jasper. We did not find arrowheads but scrapers and worked edges.

Top to bottom: a scraper made of jasper (metamorphosed chert); a chalcedony working edge; a bit of a 'hatchet' made of chert [??].

Nothing too cool but we only spent two hours out looking around. Honestly these were the most confusing things I ever looked at. At first things looked like debris, then I noticed working edges and differential polish. None of it made any sense. Perhaps the smaller items were multi-purpose.

Worth the 100 miles just to be there:

I get a laugh, zooming in on this one. Where else could you pee and scan a horizon like that?

A bit later, we walked over to Arrowhead Windmill. The water tasted a bit chalky, there were no arrowheads underfoot, but there was a bit of a structure I did not understand:

These were the only rocks visible on the surface. 

That was at the very edge of the grasslands. There is un-restricted camping throughout [in most of the Boulder area you can see nature only through a barbed-wire fence] so it would be fun to go deeper in, finding better wetlands, and spend a week basking in the emptiness.