There's a small creek that runs right past it. They looked like river rock to me, but they weren't anywhere near the water. They were in piles of dirt that had come loose from the side of a hill. This was an old quarry that hadn't seen any use for a while.
What's fascinating to me, is how many years it must have taken for this to happen!
Back in 2011 I bought a mountain in Virginia. That same year I built a hunting cabin on it, right up on top. There are rocks everywhere up there. Some have beautiful clear diamond like crystals in them. I asked some of the locals what they were and was told by several different people that it was called "quartz outcropping."
I had a well drilled and it had to go 900 ft deep to get water. What came out of the hole looked just like dark gray aquarium gravel until he got to 600 ft down inside the mountain. He hit a layer of mud and thought it might break thru during the night and have water the next day...of course, no such luck. But, when he started drilling again the drilling rig kicked out a bunch of nice smooth rounded river rock that looked just like {or very similar to} the ones pictured in this thread. He said he drilled wells for 40 years and never seen worn smooth rounded "river rocks" get kicked up from 600 feet down. Must have been an underground river down there at some point in time.
Finding rocks around a gravel mine they could have been been dug up from another location near where you found them and put there as part of the operation. We own/operate several gravel pits and material gets moved around quite a bit during the course of operations.
Those rocks with the bands on them almost look like they could be some type of sandstone.