• What to do: Prehistoric travelers hiked the ridge top separating watersheds in what is now Greene County to obtain flint from the Flint Ridge area of Ohio and to conduct commerce. In use for about 5,000 years, local Indians frequented Warrior Trail, which crosses the county six miles north of the Mason-Dixon line. For 45 miles, it follows a ridge separating the drainages of Whiteley and Dunkard Creeks; for the next 22 miles it follows the watershed separating Fish and Wheeling creeks in Marshall County, W.Va. First studied in the 1930s, the trail is the site of numerous archeological digs.

• Contact: For more information and a travel guide write to Warrior Trail Association, PO Box 103, Waynesburg, PA 15370-0103.