BNSF took back the Butte-Garrison line on Oct 27, 2003. At the start, the Copper City Sub was a stand alone subdivision with their own BNSF timetable. On Dec 02, 2009 they became part of BNSF's Montana Division with the issuance of timetable No. 8.

BNSF (or BN) did have concerns that MRL could route traffic through the Silver Bow Gateway to UP. But frankly that point may be moot these days as originating on-line traffic for MRL isn't what is used to be back 25+ years ago when MRL started. MRL can't just run the BNSF overhead traffic that way; not their perogative. Besides, there are a few additional passes to get over routed via UP if headed for the West Coast. Back when MRL still had the Stone Container pulp mill west of Missoula, there was a lot of traffic that went south to Salt Lake City and LA. That mill closed several years ago. I believe the labor contract inherited from Montana Western was retained and is it still different than the national contract on BNSF.

Currently, the power used is a pair of SD60s as they are somewhat plentiful for BNSF. They do keep at least one second generation Geep around to switch local industry and go out the old MILW line south of Butte to Newcomb. Their local train to Garrison runs Monday through Friday.
Dave Franz
Missoula, MT