Steady climb with a terrific payoff at the top
We rode on a hot, humid Memorial Day from Cumberland through Frostburg, on to the Big Savage tunnel and then the small crossroads of Deal, PA, 50 miles round-trip. The surface is in excellent shape with only a few very short stretches of loose gravel. I rode it on my road bike with 700x23 tires with a little bit of tread, but it would have been fine with narrower slicks.
On a map of the route from Pittsburgh to Washington, DC this climb looks to be monstrous. Actually the grade going uphill is not very severe, but it is relentless! Only one brief downhill in over 23 miles to the subcontinental divide separating the Great Lakes and Atlantic basins.
We had no problems riding through the tunnels, which were wide and easy to see in, unlike at home in Wisconsin where every tunnel seems to be curved (so you can't see the other end) and lined with flat black rock that absorbs every bit of light.
There is a row of concrete barriers at the state line, presumably to keep Pennsylvania ATVs from crossing into Maryland, a helipad and a big "Crossing the Mason-Dixon Line" sign. The surface in Pennsylvania was just as good as Maryland. Deal, PA had a picnic table and porta-potty, as did a few other places along the way, but there was no water anywhere along the trail. We had several bottles in a pack on my bike, and refilled afterward at the C&O Canal visitor center in Cumberland.
Temperatures were noticeably cooler at the higher elevations, and the downhill ride back to Cumberland was easy and fast. I hope to come back some day and ride the more of the route in Pennsylvania.