State police are investigating a two vehicle crash involving a tractor trailer eastbound on Route 422 in Clearfield Township.

The crash was initially dispatched at 5:44 p.m. and investigators were still on the scene as of 9:30 p.m. Traffic was stopped between the intersections of Moran Road and Clearfield Road along Route 422.

According to Butler County 911 dispatcher correspondence, a medical helicopter was put on standby earlier in the evening.