Actually, there are several places to stop right off of I-90. Starting with The loop road through Badlands N.P. When it comes back to I-90, you're in Wall, SD. home of Wall Drug Store. You will have been seeing signs for it about the time you pull out of your driveway. They advertise free ice water on the signs. The place is huge but you have to stop if for no other reason to get your picture taken on the concrete statue of a Jackalope. A jackalope's bottom half is a jack rabbit and the top half is an antelope head, complete with horns. Rumor has it that they're only seen late at night about the time the bars close.
Next, is Rapid City, SD. Head south on 16 to visit Mt. Rushmore, Crazy Horse Monument, Custer, SD, and Wind Cave.
Shortly after that, you'll see the detour for Devil's Tower. A huge rock with the top chopped off. That's where "Close Encounters of the Third Kind" was filmed. Next stop on I-90 will be the Little Bighorn Battlefield where General Custer severely underestimated the size of the enemy.
Then continue on I-90 to south on US 89 to Gardiner, MT. That's the north entrance to Yellowstone N.P.
Retired and visiting as much of this beautiful country as I can.
