(September 11, 2018, 2:15 PM EDT) -- GREAT FALLS, Mont. — Two Native American tribes sued the U.S. government Sept. 10 in Montana federal court to halt construction of a crude oil pipeline across the United States, saying officials approved the project at the direction of President Trump without conducting required environmental and historical studies (Rosebud Sioux Tribe, et al. v. U.S. Department of State, et al., No. 4:18-cv-00118, D. Mont.)....