[winner]

Hi Chris again:
I must tell you that we are planning to spend two (2) days at Custer, SD (US Hiway 16) Just inside the Border of SD Off I-90 at Sturgis. CUSTER STATE PARK is about 3 miles out of the town of Custer - Check your Rand & McNally. We are planning to stay at the Custer/Mt Rushmore KOA.
With regard to Emergency - We have the best there is USAA
Being retired military, they have the very best Road Service Costs us $4.00 a year - I have already had my Motor Home towed 18 miles on a previous trip. With regard to Gas - My tank holds 80 Gallons, so I don't have to seek a station at frequent intermals. All "US Numbered" highways are not backroads - they are first class scenic highways - nothing like the sterile speed lanes of the Interstate System. Distances of 300 miles in our Great West are nothing.