Mobil Grain was established in 2005 to provide mobile grain handling facilities, but the company became a railway operator in 2009 when it acquired and reactivated the 136km former Canadian National (CN) line from Regina to Davidson in Saskatchewan, which is now known as the Last Mountain Railway (LMR).

Following the successful revival of the LMR, Mobil Grain went on to acquire 402km of CN branch lines south west of Saskatoon, which operate under the Big Sky Rail brand. To connect BSR with the LMR, Mobil Grain has running rights to operate over CN's Saskatoon - Davidson and Saskatoon - Delisle lines.

The company also owns the Mobil Ex grain terminal, which is located on the Mission River at Thunder Bay, Ontario.