Lots of what-ifs out there. Here's some of mine . . .
White if UP had never lost Colorado & Southern (and South Park had made it to Grand Junction)?
What if Rio Grande had never lost Western Pacific (and had merged with MoPac)?
What if Rock Island had purchased both Colorado Midland and El Paso & Southwestern (both natural extensions)?
What if Burlington had purchased Denver & Salt Lake and extended it to SLC (and gotten rights on WP or acquired half-ownership of it)?
What if Santa Fe had made it to Leadville?
What if Southern San Luis Valley had made it to Taos?
And so on and so forth?

Today? What if BNSF and UP made a deal which brought DRGW back to life to run both all DRGW & WP. (And while we're at it, it might as well take over what's left of UTAH, which is abandoning most of it's main line).