Found on large rocks at the path crossing over Village Creek.

I spent a beautifully sunny afternoon exploring Village Creek Historical Area in Arlington. I used to go there for a little nature on my lunch hour when I worked nearby, but never to look so closely like I did today. It's also got a fascinating history.

"Archeological excavations along Village Creek unearthed evidence of several prehistoric villages. Artifacts from the area date back almost 9,000 years and represent a culture of food-gatherers and hunters. In the 1830s, the valley held one of the largest concentrations of Native Americans in the region. Village Creek was named because of the Native American villages along its banks."

City of Arlington (Texas) Parks & Recreation
http://naturallyfun.org/village-creek-historical-area