Seneca Rocks is a visually striking razorback rock formation composed of quartzite and rising 270 meters over the surrounding terrain in West Virginia. The rock is composed of fine grains of sand that were laid down 440 million years ago and compressed at the edge of an ancient ocean. The rock was then uplifted and folded as a result of tectonic forces. Millions of years of erosion has given it its chiseled appearance today, unique in the eastern U.S.