In western Frederick County, you can find fossils dating back to the Devonian and Silurian periods of the Paleozoic Era, about 400 million years ago.
A good fossil collecting site is located alongside Route 50, beginning 0.1 miles west of the Hebron Baptist Church and 11 miles west of Winchester.
Information on other sites is available at the Shenandoah Valley Discovery Museum on the Old Town Mail in downtown Winchester.