West of Chamberlain the trackage is not operated but railbanked by the state of South Dakota for future use if needed. Check out Vivian, Okaton, and Kodoka views in this album.
West of Kadoka the rails are removed for about 70 miles until just about 5 miles east of Rapid City.
3 Pages of Thumbnails and explanations at this link.
http://railroadfan.com/gallery/thumbnai ... album=1550
Coil cars plug the old elevator siding at Kimball, SD looking west down the Dakota Southern (exCMSP&P) towards Chamberlain and Rapid City.