In the late 1800s, the Fairmont, Morgantown & Pittsburgh Railroad was constructed, linking the Grafton-Wheeling line of the Baltimore & Ohio Railroad at Fairmont with the Cumberland, Maryland-Pittsburgh line of the B&O at Connellsville, Pennsylvania. A few years later, businessmen in the Morgantown area chartered the Morgantown & Kingwood Railroad to build southeast from Morgantown to tap coal mines in the area, but the line progressed only a few miles before financial support gave out.

Stephen B. Elkins, U.S. senator and industrialist, purchased the railroad a few years later and extended it to the B&O main line at M&K Junction near Rowlesburg. The line was completed in 1907 and until the late 1940s served about 15 coal mines. It also operated as a secondary through route between M&K Junction and the Fairmont, Morgantown & Pittsburgh Railroad at Morgantown.

The B&O leased the Morgantown & Kingwood in 1920 and totally absorbed the line in 1922. After the B&O takeover it was known as the M&K branch. In the early 1970s, the line was severed between Kingwood and Reedsville. Then trains out of M&K Junction or Morgantown had to serve the two disconnected segments of the branch railroad. Two coal mines continued to ship coal until 2000.