Three foot was the most common narrow gauge in the USA.
In 1976 my employers held a conference in the USA and afterwards I took a few days vacation. I visited the East Broad Top Railroad in Pennsylvania, a three foot gauge coal hauling line which had shut in 1956 but remained intact - locos, rolling stock, buildings, structures all survived with five miles of the line used for tourist trains.
Over the intervening years the EBT had its ups and downs before shutting in 2011.
But better news in 2020 is that a new organisation has been formed to get trains rolling once again. And everything I saw in 1976 is still there and still intact!
The headquarters are at Orbisonia (Rockhill Furnace) , here is the loco depot for the road's six Baldwin 2-8-2s. On my visit loco 12 was working, 14 and 17 looked workable; 15 was under repair; 16 and 18 were out of use.
The day I visited, 13 June 1976, No.12 'Millie' was the working loco. It is on the one man operated turntable which had been repositioned to allow it out of the roundhouse.
No.12 comes off the turntable ready to go and pick up its train. The building behind the loco is the Blacksmith's shop.
There was more than one departure from Orbisonia and I was able to ride as well as take photos on the line. Passengers wait at the station as No.12 trundles past on its way to turn itself and the train on a wye before coming back into the platform.
Engines work chimney first both ways thanks to a wye at each end of the line.
With passengers aboard No.12 steams past the Freight Office with hopper wagons just waiting for a loco to come along and take them to the mines.
The loco taking water alongside an old coal loading dock.
No.12 and train cross over a creek.
There are still lots of hoppers in the sidings, adding to the impression that coal trains could start up again.
A wonderful narrow gauge railway capturing the atmosphere of a coal hauler, even the dull weather on my visit seemed right for a coal mining area. There weren't many folk around - I suspect when it reopens you will hardly be able to see the loco and train with people everywhere, but good luck to all involved!
https://www.pennlive.com/life/2020/02/after-eight-year-hiatus-the-historic-east-broad-top-railroad-plans-to-get-back-on-track-with-new-owner.html has more details on the 2020 plans to reopen the EBT.
Brief history and maps http://www.okthepk.ca/publicArchive/201011eastBroadTop/map01.htm