Uintah extension to Bonanza

In Rodger Polleys excellent book on the Uintah, he shows a plan for the proposed extension to Bonanza, which would , if completed , have meant a longer life for this unique railway. in my insane quest to recreate the railway using the 3d simulator Trainz , I'm also going to build the extension using this map.

I was wondering if anyone has any further info on the extension ? it would have been very costly, including four major bridges of around 500 foot length and 150 ft high, and numerous trestles ( I've laid the route following the proposed map and I cant see them using less than 18 in the route from Watson to Green river alone, its supposed to be " relatively flat " but that's a bit like saying the surface of the moon would make a good bowling green :- )

Once on the other side of the Green river it would still have been a formidable route, with 6 percent grades climbing to the Gilsonite fields at Cowboy .
Anyone have any thoughts or further info on this pipe dream from the 1920s ?