i covered the bulk of the Great Allegheny Passage trail from Connellsville to Cumberland in two weekend trips recently. the first was 98 miles in two days from Connellsville to Rockwood and return. the other was an overnight trip from Cumberland to Rockwood and return - i logged 92 miles total for that trip.
it was awesome weather and the fall colors were incredible. i highly recommend this trail - the total distance is 135 miles and can be done in two days. it can also be used as part of a multi-day trip to DC from Pittsburgh using the C&O Canal.