The Missouri Pacific served the Port of Lake Charles with a branch line, the Lake Charles Branch. Union Pacific acquired MP in 1982, and then acquired the Southern Pacific in 1995. Some time around the SP merger the Lake Charles-area lines were consolidated. A segment of the MP line was abandoned, due to lack of traffic and customers along the line. This segment had a junction installed with a remnant of SP's Lake Arthur branch.
This abandonment also includes a reroute of the existing line around the Chennault Industrial Airpark with the extension of their main runway.
Thanks to Mike Palmer for contributing information about this route.