The image is a photograph of a sign posted on a wooden post in a wooded area. The sign is rectangular in shape and has a beige background with black text. The text on the sign reads "MUAV LIMESTONE marks the last and deepest phase of a Cambrian sea. Algae were abundant in this sea. These primitive plants produced calcium carbonate, the building material of this formation." Below the text, there is an illustration of a bright angel shale, which contains fossils of trilobites, marine crustaceans, and abundant evidence of early animal life on earth.