what gauge were Uintah mine trams ?

I'm hoping someone has info on this, the guy who is building Uintah 3d models for the Trainz simulator for my Uintah route is constructing the mine tipple at Carbonera and the question of the tram gauge came up. The trams look pretty wide to me , near to 36 inch, , but he's arguing that it seems silly to have the mine the same gauge as the railroad, it certainly looks wider than 2 foot, , but we have few reference points to work from, Unfortunately Rodger Polleys books don't mention the gauge , it looks at least 30 inches to me , can anyone help ?
One other thing, I know Rodger was active on here a while back, i can access some of his posts ( although its really time consuming to find ones from 12 years ago ) but any visuals he included are no longer available) , has anyone saved any items he posted here that he didn't include in his books ?