Side A: For more than 10,000 years, Flint Ridge was one of the most important flint quarries in eastern North America. The flint formed at the bottom of a shallow ocean 300 million years ago. The softer rocks surrounding the flint have washed away, leaving the hard flint exposed near the surface. Prehistoric people came here to quarry the flint, which they crafted into a variety of stone tools. Hundreds of quarry pits and workshops are scattered for miles along this ridge. The beautiful rainbow-colored flint was especially prized by the Hopewell culture that built the nearby Newark Earthworks. Artifacts crafted from Flint Ridge flint may be found throughout eastern North America. In more recent times, local industries quarried the flint for use as grindstones.