Thanks, Brian! That's exactly what I was looking for.
Looks like I'll have to grid 1.5 miles X 3 miles. Probably take more than an afternoon!
Knew I could count on TFL!
Mike, it was an Indian massacre, not a robbery. The Indians were on foot, and cut mesquite bushes to stick in the ground for concealment. There were 15 of them, armed with Henry & Spencer repeaters, but they only had two rounds per weapon.
That's probably why there were two survivors.