From Cajon you could just stay on BNSF with a third rail all the way to Trinidad via Raton. From there connect to Chama via Walsenberg, La Veta and Alamosa. Adding a third rail might cost less than an entirely new line from Gallup to Farmington and rebuilding lines that have been gone for over 35 years. On the other hand, there would be have to be a lot of frogs added to switches on at least one of the mains, even if there were no NG sidings.
And it's the long way around - over 1200 miles at 30 mph* ...
- El Curmudgeono muy Loco
* Per some stories I've read, the K-36's sometimes hit 40 between Antonito and Alamosa. The Kiwanis Kolor Karavans in '62, '64 and '66 felt like they were going at least 30 on the last leg of the trip.