The Lionel 6-8771 is an O-gauge Great Northern U36B Diesel Locomotive released in 1977 during Lionel's popular Model Products Corporation (MPC) era. It served as the flagship, "powered" command engine heading up the top-of-the-line "Rocky Mountain Special" train set (Set No. 6-1765). Because it was sold exclusively as part of that set, finding the locomotive individually outside the original collection can be quite difficult for collectors.
