Mr. John,
I see that I-70 runs right through Abilene, KS, where Dwight D. Eisenhower has his Presidential museum (very interesting). If you like looking at houses/architecture, the Seelye Mansion is also in Abilene. There is also the Kansas Auto Racing Museum (I haven't toured yet, I'm a car nut).
If you are plan on staying in the Denver area, make your reservations NOW! We have never been able to stay in the city, always full when we pass through.
The Zion National Park in Utah is beautiful. The I-70 ends at the I-15. If you haven't ever been to Las Vegas, it's a must see!
Where out west did you want to end up?
Safe travels,
MM.