For continuous running on a point to point layout another possibility would be to put a 4x4 section on each side of the door to allow a turnback curve. You could then either have a reverse loop at each end, or make it a long folded dogbone that would look like a double track mainline between the turnback curves. If you are modeling Santa Fe, the mainline between LA & Chicago is mostly double tracked. If you put Raton Pass in the middle of the layout, you could model plains on the Eastern (North) side and high desert red rocks of Arizona/Colorado on the Western (South) side of Ratone.
Basically the Santa Fe mainline runs East out of Los Angeles to Riverside & San Bernardino where it turns North to go through the Cajon Pass. On top of Cajon Pass it turns East again to Albuquerque, NM where it makes another turn to the North to go up into Colorado, over Raton Pass and on to Chicago. In the plains, you could put in sidings with grain elevators as a source of freight. To the West Santa Fe had one of the largest fleets of ice reefers in the country hauling iced produce (especially citrus) out of California to the East Coast via Chicago. At the same time, there was a thriving meat packing district in Los Angeles that was the destination for many livestock cars. Also Armour, Swift, Morrell, and Rath packed a lot of meat in Chicago and shipped it out to the West Coast as well as stops in between.