I spend as much time in Summit County, CO as I can each year. During early fall the Colorado Rockies are probably one of the best places you could be with a scooter or motorcycle. Even the 3 miles from our house going into Breckenridge is a joy coming down (or going up for that matter) Boreas Pass is fun.
Miles of lovely state highways that are well maintained, in good condition and a pleasure to ride whether they have twists and turns or cross valleys. Though some of the side roads can have unexpected hazards like pups.
Or and deer or elk that can’t be trusted to stay off the road.
While some of the loveliest places to ride are dirt. Which can be a lot of fun provided that they have been recently graded and are dry.
While they warned us when we entered Mt. Evan National Park that there were frost heaves that could be dangerous for motorcycles I thought they led to a fun rollercoaster sort of updedoo.
I do suggest no matter when you go up to Mt. Evans layers are your friend.