Google says 494.6 miles,and 9 hours, 30 minutes.   If you can do it all in 9 1/2 hours, you’re gonna miss some great stuff!   

Google Map Route
SD-240, Philip, SD 57567
Scenic, South Dakota 57780
Rapid City, South Dakota
CrossRoads, 20622 Fort Meade Way, Sturgis, SD 57785
Belle Fourche, South Dakota 57717
Alzada, Montana 59311
Sundance, Wyoming 82729
Hot Springs, South Dakota 57747
Custer, South Dakota 57730
US-16 Scenic, Custer, SD 57730
Keystone, South Dakota 57751
Deadwood, South Dakota 57732
Sturgis, South Dakota 57785