Years ago while going to Philmont Scout Ranch from San Antonio, we traveled 39/56/412 from Logan to Springer. At that time, no traffic, two lane road, no real towns, nice scenery, typical NM ranch country with the road going up the hills and down over the bridges over washes. I would not hesitate to pull my 38 foot 5th wheel over that route but would not expect to make great time. Hope someone else has current info for you.