My wife and I rode Highway 20 from Oregon to Boston. It went through Lusk and Douglas, and is a good route. You can check out some of the ride details at our blog site. Just click on 2007, and check out the end of July and early August. It is not real easy to navigate because of the way we posted them, but you'll get the idea. Actually Highway 20 was a great route. It is the only contiguous highway in the US that runs from coast to coast. It was a little tough from Oregon to Nebraska. It was more the temperatures than anything esle. We hit one day with a temperature of 109 F in eastern Oregon. Many +100 F days. but it was still great riding. We wanted to ride it since it goes right by our house. On our second night heading east from the Oegon coast we "camped" at our own house. We also like to stay off the ACA routes for a number of personal resons. Yellowstone is great on a bike!

http://ddlivestrong.blogspot.com/

Good luck on your ride, and don't let folks tell you that the prevailing wing is always from the west!