I pulled out my copy of Bender's book on the Unitah. As I recalled the #30 worked only on the north side of Baxter Pass and was disassembled for the trip over the pass.
Bender tells on page 99 that when the #30 arrived in 1911, it ran under its own power to Atchee. There it was jacked up and the driving wheels were removed. The frame and the boiler were placed on a couple of freight car trucks and it was moved slowly that way over the pass. Then it was reassembled on the other side. It never made a return trip!
#40 was sent over the pass when it arrived. And then it was brought back when the 2-6-6-2Ts arrived and that allowed the railroad to retire most of the 2-8-0s used on the south side of Baxter Pass.
Any second-hand buyer would have to do the same thing to move the locomotive to any new location of use. So #30 was cut up on the north side and returned south in pieces.
Brain Norden