Deadwood is 40 miles north of what you want to see. An interesting drive thru but not a good base of operations. The Hill City area is where you want to be for Rushmore and Crazy Horse. Several nearby RV parks. And another 10 miles south gets you to Custer and the SP. Drop off the TT or 5er at a CG before you start touring. Needles highway has many tunnels and turns that you don't want to drive while towing. Narrow tunnels, "pigtail" bridges and 180 degree switchbacks. When you see them, you'll know why they call them "pigtail".