Here is a list of crushed gravel trails available in the area:
Pittsburgh to Cumberland (then C&O Canal Trail to Washington DC)
Greensburg to Armbrust (Westmoreland)
Slickville to Saltsburg (Westmoreland)
Blairsville to Saltsburg (Westmoreland/Indiana)
Wheeler Bottom to Dunbar (Fayette)
Forbes State Forest to Linn Run State Park (Westmoreland/Somerset)
Jones Mill and Indian Head to Champion (Fayette)
Scottdale to Mt. Pleasant (Westmoreland)
Ebensburg to Black Lick