If you'll allow me to wax nostalgic for a moment, I've had an itch to know what something was for the longest time. Back in the late 50's we used to take old 66 from St. Louis to Rolla to see my grandparents and the highlights of the trip were a stop at the Diamond and going through Pacific. The "caves" on the north side of the road were mysterious and unknown to a kid (rather mundane when I found out what they were) but the itch I need scratched is what was on the south side of 66 and the tracks (straight south of the caves)? If memory serves it always had a cloud of dust over it and always seemed quite busy. Were these the gravel pits or something in support of the silica mining or something else entirely? Sounds silly but you know what an itch can do to you to you. Thanks in advance. Larry F.