They were also in use at the old DEN (Stapleton), as well as STL back in the pre-Ozark merger days. At STL, Ozark had some gates on the west side of the C-concourse, and they'd also line some of their DC-9s up behind and parallel to the C-concourse and use the people movers to shuttle passengers between the various aircraft and the elevated "J-Dock" that was located in the side of the building where the C-concourse went into the terminal. (This was long before the current D- and E-concourses were built, and those areas were all still freight area and hangars). Making a connection on Ozark back then was always a challenge...