What part of Colorado are you heading too?
There are a lot of historical stops along I-80/US34 in Nebraska such as Pony EXpress and wagon trains. Scotts Bluff is interesting. The SAC air museum is between Omaha and Lincoln, NE just off of I-80. It is worth a stop.
In Iowa is the Motorcycle Museum started by the owner of J&P Cycle in Anamosa, IA. It is nice. Of course if you want to spend money J & P Cycle is there too.
Near La Junta, CO is the Bent's Fort. Sand Creek Massacre National Monument is near there also but on a dirt/sandy road. My uncle rode into there on a GW. I did not try it on my X or RSV. I was in a van when i visited it. It gave me a very sad feeling.
Colorado highway 12 from Trinidad west is very nice. Then US 160 west to Durango is a good ride. Just be careful of the deer/elk in the mornings and evenings. West of Durango is the Mesa Verde. Then there is the Million Dollar Highway, US 550, and Silverton. US 50 from where ever you want to get onto it through Colorado is great.
I really liked the ride up Mt. Evans, the highest paved road in North America. It is higher than Pikes Peak. In the NW there is Dinosaur National Monument.
Once in Colorado and west of I-25 just wonder and you will enjoy it. Open up a map and pick a road. You can't go wrong. The I-25 corridor is a nightmare and this comes from a guy living in the Dallas-Ft. Worth Metroplex.
as used on Race Tech site
rode 07 Black Cherry VTX 1300R
States+DC & 11
i,both w/aux tank & Race Tech SuspensionIBA:Mile Eater Bronze &Silver,SS3000,3xSS2000,EclipseSS1000Gold, 20SS1000,6xBB1500,3TX1000,NPT 29/76; Lake Superior Circle Tour
15 to 20K per yr between the two MCs