Jim, Judy and Roxie:
Yup, you'll have no problem with the Cheyenne Crossing to Spearfish route. Last spring (May/June 08) they were working on a little re-construction project just NW out of Cheyenne Crossing but even that wouldn't have been a problem.
Now....WE came up to Cheyenne Crossing from Newcastle, WY on Hwy. 85 with our 45 ftr. towing car and went straight into Lead/Deadwood from Cheyenne Crossing. Gotta tell ya it's quite an uphill pull from the Crossing on the way to Lead, but even that route is doable.
We're pretty familiar with, and just love the Black Hills area and sure hope you enjoy it also. Don't forget to take a day trip up to Devils Tower, and......DON'T overlook stopping at Cheyenne Crossing for a piece of really good apple pie!!!
Steve & Lynette