BILLINGS, Mont. (AP) â¿¿ An environmental group has filed a lawsuit in federal court seeking to overturn government approvals for seven coal mines in four states. Jeremy Nichols with WildEarth Guardians in Denver said Thursday that the Department of Interior's approvals were illegal because no public notice was given. At issue are mining plans for the San Juan mine in New Mexico; Colowyo and Trapper mines in Colorado; Black Thunder, Cordero Rojo and School Creek mines in Wyoming and Spring Creek mine in Montana. A lawsuit filed in U.S. District Court in Colorado asks a federal judge to void the government's approvals, which were awarded between 2007 and 2012. The suit contends coal mining pollutes the air, water and land. The Department of Interior did not immediately respond to a request for comment.