We spent a bit of time here talking about the geology of the area. This is argillite that was under water at one time. You can see mud cracks and wave lines on various parts of this rock. To hear more of what Jeff said, I covered some of it in my video [ youtube video ]

Common Belt series rocks found in Glacier include the Appekuny, Prichard, Grinnell, and Snowslip Formations. Reddish-brown and greenish-gray in appearance, these rocks are comprised of argillite and quartzite material that was compressed under sea water to form mudstones. The chemical composition of these rocks, in addition to their place of origin within the Belt Sea - near shore versus deeper water environments, is largely responsible for the variation in color.