A few highlights from the article:

"If we put a project like this in around Yellowstone County, in that river valley, it’s gonna be an environmental impact similar to a coal mine, or something that’s gonna cause irreparable harm to the area. I think that’s why there’s so much opposition to it right now,” Doyle said."

"The gas would affect more than just the rural Broadview community. A retired Billings pulmonologist modeled the air-quality impact of 1,700 megawatts using EPA tools, Hedges said, and found fine-particulate pollution spreading to communities east of the site, including the Crow, Northern Cheyenne, and Fort Peck reservations. “It’d be a disaster,” she said."

Edit: A bit more detail below from the article on the data center it discusses.

"The stakes are highest in Crow country. In the small city of Hardin, at the Crow Indian Reservation’s northern edge, a former cryptocurrency mine is being actively converted into an AI data center. About 14 miles northwest of the reservation, Texas-based Quantica Infrastructure plans to build its Big Sky campus on nearly eight square miles of ranchland near the town of Broadview, north of Billings, Montana’s most populous city. As it’s currently planned, the data center would rank among the largest data centers in the world. The Yellowstone River Valley is “the heart of the Crow Nation,” Doyle said."