Navajo environmental groups are asking a judge to review actions that led a federal agency to renew an operating permit for a coal mine near the Arizona-Utah border.
The federal lawsuit filed Thursday alleges the Office of Surface Mining, Reclamation and Enforcement didn't properly account for the Kayenta Mine's expected closure in 2019.
The groups say they want assurances that Peabody Energy will restore the land to pre-mining conditions.
The federal agency didn't immediately respond to messages left late Friday.
The Kayenta Mine is the sole supplier for the Navajo Generating Station near Page, Arizona. The operating permit expires in July 2020.
The owners of the generating station are closing it in favor of cheaper energy produced by natural gas.
Peabody is trying to secure new ownership for the plant.
