I 435 to Kansas 5 highway, north. This is the 1st exit on the Kansas side if you are coming from Missouri (or last, if you're coming from the south). Going north on 5 highway, you follow 5 through 2 quick stop signs. Then the fun starts....almost 10 miles of pretty twisty road. Speed limit is 55 most of the way...drops to 40 in several places. Numerous "S" turns that are rated between 20 and 35 MPH...but of course, we took them at 40 to 50 MPH!!. A nice time to go is on a sunny afternoon, because as you near Leavenworth, you go by the Lansing Correctional Institute...the inmates that are playing baseball love to wave at Mini's

Very fun drive.
Another good tip, especially if you have a navigator that is itching to drive the Mini...5 runs into 7 highway...you can turn left and go several miles to the Lansing Dairy Queen. Buy a Freeze or a Blizzard to share, then change drivers, so you are now the navigator. You'll get to enjoy most of the Freeze/Blizzard, cause the driver now driving south on 5 will have to have both hands on the steering wheel to get the most out of the drive!
Once you get back to 435, you could go straight and then drive through Wyandotte County Park....once you get to a T intersection in the park, turn left and head for the dam....it's several miles away, on a very twisty road (but only 20 MPH

Let us know if you try this route...we loved it and hope you do too.