My thought's as well!! Looks like there was alot activities around the big boulder! That is the 3rd or 4th piece made from the Zebra flint.

I didn't know Kerville knifes were found that far West?

Back to Dr Hesters' new edition again,,very good description including range.
Other than the shaded range limits, Amistad Resevoir is specifically noted and that is less than 30 miles due south of the Juno site.
That I know of, 5 KK's ( 1 of my own ) have been found at the Juno dig, could be more not reported.

Trav...Dusty & dry is certainly a way of life at the site. What pics cant properly convey is that a strong wind compounds the effect immensely...
Imagine having a Bobcat bucket load of black talcum powder, lift it up and drop it from a height....with the wind blowing sideways
After a dig, most people wash off in the river, thats why is looks so murky downstream.

Sandy, Probably due to the soil composition, ALL pieces of flint is found with a coating of dirt ( not scale ) that removes easily with water...ZERO pieces ever tumble out with any flash of color. Almost all the flint has some sort of good SW Tx variety...When a happens along it's a bonus.

the good thing about talcom poweder is that it sifts nicely