Always glad to help. Links follow the citations below. Do you know when your ancestors made their journey? It makes a big difference.
The mountains were an early, natural barrier. Completion of the National Road through to Wheeling in 1818 made overland travel south of the mountains to the Ohio River much easier. Completion of the Erie Canal in 1825 made a northern route west feasible.
My ancestors traveled earlier than that, from Canisteo NY to Louisville KY with six small children. It seemed horrendous to me before I studied maps and modes of travel in 1815. I was able to determine their route covered only 60 miles overland to Olean, where a tributary of the Ohio River was perfectly navigable to Pittsburg.
Drake, Samuel Adams. The Making of the Ohio Valley States, 1660-1837. New York: Charles Scribner's Sons, 1894.
http://archive.org/details/makingofohiovall00drakDwight, Margaret Van Horn. A Journey to Ohio in 1810.
New Haven: Yale University Press, 1820.
http://archive.org/details/journeytoohioin1017325mbpFaris, John T. On the Trail of the Pioneers. New York: George H. Doran, 1920.
http://archive.org/details/ontrailpioneers00farigoogMatthews, Lois Kimball. The Erie Canal and the Settlement of the West. Paper read at the Conference on Western History, meeting of the American Historical Association in New York City, 30 December 1909.
http://archive.org/details/eriecanalsettlem00roserich