SWP provides local service to many customers in the area, connecting them to the outside world via interchanges with Norfolk Southern, Wheeling & Lake Erie Railroad, and CSX.

Near the end of the line in Smithfield is a new large fracking-sand facility owned by Hi-Crush Partners, which receives 40 ft covered hoppers.

The Southwest Pennsylvania Railroad began operations in June 1995 when Trimax (now Carload Express) was selected to operate 66 miles (106 km) of railroad by the Westmoreland County Industrial Development Corporation and the Fay-Penn Industrial Development Corporation.

In May 2000, the Southwest Pennsylvania Railroad started service to the Westmoreland Rail Freight terminal near New Stanton.

The railroad began service to the Hunter Panels plant in the Fayette Business Park in Fairchance in 2006.

In 2011, the Southwest Pennsylvania Railroad commenced service to the Fayette Rail Freight terminal in Smithfield.