Then certainly consider Black Canyon of the Gunnison, Great Sand Dunes NP, the US 550 stretch between Grand Junction (proximity of Colorado National Monument) and Durango through Ouray.

Between Great Sand Dunes and Santa Fe you can drive the High Road to Taos and also visit and camp near Los Alamos at Bandelier NM (good hiking and viewing at Bandelier and nearby Los Alamos is full of history). The High Road to Taos is the old Spanish Mission route between Santa Fe and Taos, so allocate a few days for this. There is a lot of information on the internet about these sites so I won't try to repeat it here.