I make the trip from S TX to NE WA twice a year. The shortest friendly rout I have found is' McAllen to San Antonio to Albq or Gallup to Shiprock, to Moab, to Salt Lake, to Id Falls.
Stops things to see: Mesa Verde NP, Canyon Lands NP, Arches, NP
Take a look at this thread.
Hills or 2-lane and Wind or 2-lane?
If you don't have a copy of MS Streets and Trips, I highly recommend it as a planning and mapping tool. The version with the GPS puck is great as a driving tool and GPS if you have a laptop.
04 Horizon QD, 12 Ford Flex, Excalibar, Brake-Pro, ,, Winter Texan, RVin! since 1974
Norm, Donna & Tinker Kat 74 MGB-GT, 75 MGB, 01 Z3
Life is a Timed Event, you only get One Go Around!