Great write up on one of my favorite places to explore around. My mother works for the jeep tour company. She drives from Maryland out to Custer park each year to work for the summer. This year she is 70 years old and still makes the trek, she loves that park.
I drive around with the kayak on the top of the truck pretty much all the time this time of year. Having a cover will keep out the rain and dust, but MPG effected by the open cockpit, nay don't think so..