I am also retired military and like the old trails
Two of my favorites are the Butterfield stage route of 1858 and the old Mojave road in the Calif desert.
there have been several good write ups on the Mojave road.
when I drive it I can ajmost see the camels that were used here in 1858.The good part is that you can drive it in a 4wd for 120 miles and visit a few of the old Forts.
OLD 2006 F150 4wd 7200gvw,Lt275-65-18,Scan Guage,Garmin,flowmaster,load levelers,Firestone work rites Bronco 800
NEW 2015 F250 Scab 4wd 10000 gvw, 6.2 Scan guage,Garmin,work rites,3200 lb load,1800lb Palomino Backpack SS1200