When you reach the I70, turn West. Just after Denver you'll find Mount Evans, drive up there and soak it in. Then continue West on the I70, fully appreciate the Glenwood Canyon as you go, and turn South at Glenwood Springs.
It's not far from there that you turn West again to Delta, following the Crystal River for some of the distance. No river was more aptly named. At Delta you'll find a car lot with heaps of real treasures, have a good look around them before you head South through Montrose, Ouray, over the mountains to Silverton (worth a stop) and then on to Durango. Very pretty drive, stop and appreciate it often.
Then make your way back East and then South to Santa Fe via the Rio Grand Gorge (I think that's what it's called) and on to the I40 and Texas. Unless you continue South through Albuquerque, Belen and on to El Paso as your entry to Texas.
Ray