RAPID CITY, S.D. -- Six American Indian tribes are among groups filing appeals to a federal board’s approval of the Dakota, Minnesota and Eastern Railroad’s $1.5 billion coal train project, according to a wire service report.

The Sioux tribes appealing the Surface Transportation Board decision are the Oglala, Cheyenne River, Crow Creek, Lower Brule, Rosebud and Standing Rock. The railroad, based in Brookings, wants to rebuild and extend its line into Wyoming’s Powder River Basin to haul as much as 100 million tons of coal a year to the Mississippi River and beyond.

Signs point to the 1868 Fort Laramie Treaty as the basis for at least some of the appeals.

That treaty with the U.S. government gave Sioux tribes all of western South Dakota. In the 1980s, the U.S. Supreme Court awarded the tribes a cash settlement for the Black Hills, which they refused.

Attorney Richard Streeter, who represents the Sioux Nation, said the STB’s treatment of Indian treaties likely would be one of the issues in the appeal. He said historic preservation, religious freedom, grave protection and other issues may be a part of it as well.

The deadline to file appeals to the STB’s decision was April 1.