Hambone to Lookout Jct. - McCloud River [BNSF]
The McCloud River railroad is still in operation.  However, the segment between Hambone and Lookout Junction -- owned by Burlington Northern Santa Fe but operated by McCloud River -- was last operated in December 2003 and has now been abandoned.

For more information, with this photo (and several more), some recent history and a map, plus the adventures of exploration, go to http://cbassweb.com/railroads/mccloud/lookout.htm
Thanks to Craig Bass for the information and photo on this page.
McCloud River / BNSF rails near Lookout Jct.  Last train operated in December 2003; photo from early 2004.