Visit Colorado's tripoints (points common to three states).

Here is a sample 900-mile route from Morrison CO to eastern Colorado's tripoints.
paved, gravel, dirt - street bike for most of route, dual sport for the last miles to the tripoints.

Google Maps sample tripoints route

Click on the following links for more details.

CO-UT-WY

CO-NE-WY

CO-KS-NE

CO-KS-OK

CO-NM-OK