intersects the southern terminus of Pennsylvania Route 48 in Forward Township before entering the boroughs of Elizabeth and West Elizabeth. In West Elizabeth, after crossing the Monongahela River via the Regis R. Malady Bridge, PA 51 immediately intersects with Pennsylvania Route 837. It then continues towards Jefferson Hills in the northwest, where it meets the northern terminus of Pennsylvania Route 43 (Mon-Fayette Expressway) at exit 54. PA 43 is expected to extend further north of PA 51. Northwest of PA 43, PA 51 becomes Clairton Boulevard. In Pleasant Hills and West Mifflin, PA 51 passes by the former Century III Mall, which was formerly one of the largest malls in the area. The stretch of PA 51/Clairton Blvd. continues through Baldwin Borough, Whitehall, and Brentwood. At the border of Brentwood and Overbrook, PA 51 becomes Saw Mill Run Boulevard. At the southern tip of Pittsburgh, PA 51 intersects the northern terminus of Pennsylvania Route 88 before continuing towards the north as Saw Mill Run Blvd. It meets with the Liberty Tunnel connector, which leads towards the Liberty Bridge and Interstate 579; PA 51 also begins a concurrency with U.S. Route 19 Truck at this junction. The US 19 Truck/PA 51 concurrency ends when US 19 TRK joins Interstate 376, U.S. Route 22, and U.S. Route 30 at exit 5. At this point, PA 51 begins a brief concurrency with U.S. Route 19 through the West End Bypass, a short expressway in Pittsburgh's West End section. The concurrency ends as US 19 crosses the Ohio River on the West End Bridge while PA 51 turns left, heading toward McKees Rocks to the northwest as West Carson Street, paralleling the Ohio River. Entering McKees Rocks, it makes a 90 degree turn to become Locust Street, then makes another turn to become Charties Avenue, and makes a final turn towards the northwest to become Island Avenue. In Stowe Township, PA 51 becomes Robinson Boulevard (formerly Fleming Park Rd.) and passes south of Neville Island on the Ohio River. After a couple of S-curves, PA 51 becomes Coraopolis Road and intersects Interstate 79 at exit 64. It becomes State Avenue in Coraopolis before dividing into two one-way streets called 4th and 5th Avenues. North of Coraopolis, PA 51 continues to parallel the Ohio River as University Boulevard in Moon Township. It then becomes Stoops Ferry Road and passes through Crescent Township on McGovern Boulevard