The Denver, Utah & Pacific was another of Dave Moffat's forays into conquering the Front Range via Railroad.
The original line was built from Denver to Lyons using its own grade, originally through what is now Broomfield and built to 3 ft. gauge. This line was always referred to as a "Branch Line".
The main line was to branch off of the "Branch Line" at Hallack Junction (about 100th and Old Wadsworth Blvd) and to run west, through El Dorado Springs and up and over Rollins Pass. There is a grade jutting into Yankee Doodle Lake on Rollins Pass which was DU&P constructed. The surveys ran the line through Rangely, Colorado, bypassing Grand Junction completely and yes, running through Middle Park. I have the map that shows the projected route through Colorado, so I don't know how they were going to reach Salt Lake City.
The DU&P was purchased by the Burlington, Standard Gauged and moved from its original alignment to the old Denver, Western and Pacific grade that was a UP subsidiary. The line west of Hallack Junction was abandoned. If you read the book The Moffat Road, you can see some DU&P right of way work that has been overlayed by the Denver, Northwestern and Pacific in South Boulder Canyon, as it is pointed out by the author.
Bob Richardson said that he found stacks of ties and rail in the DU&P cuts above El Dorado Springs waiting to be laid on the completed roadbed heading west when he hiked the grade.
Rick