Saltpeter caves had been employed throughout Appalachia for munitions; the border between West Virginia and Virginia includes the "Saltpeter Trail", a string of limestone caverns containing rich deposits of calcium nitrate which were rendered and sold to the government. The trail stretched from Pendleton County to the western terminus of the route in the town of Union, Monroe County. Nearly half of these caves are on the West Virginia side, including Organ Cave and Haynes Cave. In the late 18th century, saltpeter miners in Haynes Cave found large animal bones in the deposits. These were sent by a local historian and frontier soldier Colonel John Stuart to Thomas Jefferson. The bones were named Megalonyx jeffersonii, or great-claw, and became known as Jefferson's three-toed sloth. It was declared the official state fossil of West Virginia in 2008. The West Virginia official state rock is bituminous coal, and the official state gemstone is silicified Mississippian fossil Lithostrotionella coral.
Saltpeter caves had been employed throughout Appalachia for munitions; the border between West Virginia and Virginia includes the "Saltpeter Trail", a string of limestone caverns containing rich deposits of calcium nitrate which were rendered and sold to the government. The trail stretched from Pendleton County to the western terminus of the route in the town of Union Monroe County. Nearly half of these caves are on the West Virginia side, including Organ Cave and Haynes Cave. In the late 18th century, saltpeter miners in Haynes Cave found large animal bones in the deposits. These were sent by a local historian and frontier soldier Colonel John Stuart to Thomas Jefferson. The bones were named Megalonyx jeffersonii, or great-claw, and became known as Jefferson's three-toed sloth. It was declared the official stat,e fossil of West Virginia in 2008. The West Virginia official state rock is bituminous coal, and the official state gemstone is silicified Mississippian fossil Lithostrotionella coral.