Despite objections from several groups, the Harper government declared over the weekend the humpback a "species of special concern" under the Species at Risk Act (SARA).
Weak commodity prices hurt Teck's three core business units —coal, copper and zinc— but coal was particularly hard hit due to increased supply from Australia, the company said.
The Powder River Basin was the home of the top nine producing mines in the U.S. during 2013, but the number of PRB mines in the top 25 declined compared to 20 years ago, according to SNL Energy data.