Having this winter laid much of its track, they got the red flag from Craven District Council saying it needed planning permission.
Work has stopped at Bolton Abbey station, where the railway has been a feature for more than ten years.
Railway volunteers are awaiting retrospective permission before they can carry on and extend the track by another two thirds.
Railway business manager Stephen Walker said: “It’s ironic that we don’t need permission to lay track on the big railway, but it seems we do for the miniature one.
“Eventually, we’re hoping to extend the miniature railway a considerable distance to the end of the car park to give visitors a much longer ride. It’s popular with children.”