Stops between St. Louis and Santa Fe

[Mayelli]

My husband and I will be traveling between St. Louis and Santa Fe as part of a longer road trip. We'd love some ideas for things to see along the way. We only have two days to do this part of the trip, so we're looking for places that would be nice for little breaks of a few minutes to an hour each. They should be close to the highway, and we'd like places that are either free or no more than a few dollars (since we won't be stopping for long at each anyway). We have pretty broad interests as long as the places meet the above criteria - historical places, good scenery/nature, or just random, odd sights are all ok. Also, we might like to occasionally get off the interstates and do a bit of driving along back roads. Any tips on the places along the way where the scenery is most worth the extra time it would take to see it? Thanks for any advice!