This is a great moderately graded trail for running. You don't have to worry about rocks in the tread, and instead you can enjoy your surroundings.
The Dunning Trail is pretty easy as it makes its way past Pine Swamp, Pine Swamp Mine, and some lovely bald rocks. A part of this path was a mining road in the early 1900's, so those sections are very easy. Otherwise, enjoy dense hardwood forests and beautiful color in the autumn.
Since there are so many trail junctions in Harriman, you may want to consider navigating via the Trail Run Project mobile app
You can find blueberry bushes in this area, as well as lots of mosquitoes during summer. Wear plenty of repellant!