The route passes through wooded areas with some farms and development, crossing into Somerset Township and reaching an interchange with I-70.

After this intersection, PA 519 heads into North Strabane Township and passes areas of commercial development a short distance to the east of the Allegheny Valley Railroad's W&P Subdivision line, running through Wylandville.

The route curves northeast into areas of farms before turning northwest and passing through the residential community of Gambles.

PA 519 continues northwest through areas of farmland and woodland with occasional residential and commercial development, passing through McConnells Mills and Export.

and West Liberty Avenue (bordering the Pittsburgh neighborhoods of Brookline and Beechview) to U.S. 19 (Morganza Road) in Morganza/North Strabane Township.

In 1972, the northern terminus (including the remaining segment in Allegheny County) was moved one last time to its current location at PA 50 in Mount Pleasant Township.