Digging in the Wheeler Shale

I found some pictures I took while on a trip to Utah back in 2007. I was in the House Range area of Utah, west of the town of Delta, digging around in the Wheeler Shale. The Wheeler Shale (middle Cambian age) is well know for it's abundant and well preserved trilobite fossils and I was looking to add some to my collection. There are a couple of pay dig areas in the area like U-Dig and A New Dig but not many know that you can literally find trilobite fossils in at just about any exposure in the area.

This is a prospect that I saw from the road as I was driving around. Someone had come it and was digging shale out of the ground and splitting.

I looked around the spoil heaps a little and then sat down with my flat chisel to try my hand at splitting.

Some of my finds.

I think this is a worm trail or could it be some kind of algae?

Here is a shot of another, more extensive quarry where they had borught in machinery to remove the rock from a hill. Notably, the shale layers were tan in color rather then the usual light grey I'd seen everywhere else. At this site the trilobites were colored red rather than black.