Two environmental groups challenged the Montana Department of Environmental Quality’s approval of a proposed coal mine expansion in a Rosebud County District Court this week, citing the expansion’s potential to worsen the effects of climate change in Montana.

In their July 26 filing, the Montana Environmental Information Center and the Sierra Club argue that Westmoreland Rosebud Mining, LLC’s proposal to expand the Rosebud Mine into the headwaters of Lee Coulee would exacerbate climate change impacts ranging from shrinking snowpacks and increasing wildfire activity to crop losses, forest die-offs and wildfire smoke-induced air quality declines. 

Coal from the Rosebud Mine is the primary fuel source for the Colstrip power plant. Colstrip is the largest point source of atmosphere-warming greenhouse gas emissions in the state, emitting approximately 8.2 million tons of carbon dioxide per year, according to the lawsuit. 

The environmental groups say DEQ violated the Montana Constitution’s guarantee of a “clean and healthful environment” by failing to weigh the cumulative impacts associated with additional  greenhouse gas emissions from Colstrip when it approved a 2,500-acre expansion of the mine in May. They also say the Montana Environmental Policy Act is clear in its requirement that state agencies take a “hard look” at environmental impacts of projects seeking approval, including direct, indirect and cumulative impacts.

As proposed, the expansion would allow Westmoreland Rosebud Mining to strip-mine 62.3 million tons of coal over a 21-year period. The expansion would occur in the Lee Coulee headwaters, which flow into Rosebud Creek, a tributary of the Yellowstone River.

Most of that coal would be transported to the nearby Colstrip coal-fired power plant, which has an energy-generating capacity of 1,500 megawatts. A small amount of waste rock would be shipped to the Rosebud Power Plant.

MEIC Deputy Director Derf Johnson said DEQ’s decision to not consider greenhouse gas emissions in its analysis of the project violates the “look before you leap” directive established by the Montana Environmental Policy Act.

“In this circumstance, there was no evaluation whatsoever of climate change and impacts associated with the project, and that’s problematic because that’s just putting blinders on for the issue of our time,” he said. “DEQ should fully evaluate climate change impacts and the contribution of the project to those impacts. In addition, they should take the next step, which is to actually plan for a transition off fossil fuels, and to mitigate, if at all possible, for those impacts.”

According to the lawsuit, DEQ has argued that an amendment to MEPA passed by the Montana Legislature in 2011 prohibits the agency from considering climate change impacts in its environmental reviews. That amendment directs state agencies not to weigh “actual or potential impacts beyond Montana’s borders” in their project assessments. It further says environmental reviews “may not include actual or potential impacts that are regional, national, or global in nature.”

The lawsuit’s plaintiffs argue that while “effects of climate change are felt globally, they impact Montana’s environment and economy in particular and significant ways,” and that the 2011 MEPA amendment “does not absolve DEQ of its obligation to consider the climate change impacts in Montana caused directly, secondarily, or cumulatively by the Lee Coulee Expansion.”

Particular impacts cited by the plaintiffs include the disappearance of 80% of the glaciers that once existed in Glacier National Park, a “loss [that’s] irreversible on human time scales”; $2.6 billion in losses associated with the “flash drought” that struck Montana in 2017; and an expansion of mosquito-borne diseases like West Nile Virus, which has been reported in 18 Montana counties.

Johnson said MEIC and the Sierra Club raise a similar argument in a legal challenge to a natural gas plant that NorthWestern Energy, the state’s largest power utility, plans to build in Laurel. That lawsuit, filed against DEQ in October, is still winding through the court system. Johnson said he’s not aware of any existing rulings state judges have issued regarding the particular legal arguments raised by the two lawsuits.

In an email to Montana Free Press, DEQ spokesperson Moira Davin said the agency is reviewing the complaint.

Both state and federal regulatory agencies provide oversight of Rosebud coal mine expansions sought by Westmoreland, depending on the location of the expansion. DEQ said the expansion into Area B — the subject of the most recent MEIC/Sierra Club lawsuit — also includes some federal coal that Westmoreland is currently precluded from mining because it hasn’t “obtained the right to mine that coal.”

An expansion into a different region of the mine, Area F, is also currently being litigated. In 2019, MEIC and Sierra Club, along with WildEarth Guardians, 350 Montana and Indian People’s Action, sued the Office of Surface Mining Reclamation and Enforcement, a federal agency housed within the Interior Department, over its approval of a 6,500-acre expansion into Area F. 

In that lawsuit, the plaintiffs argued that OSMRE failed to consider water quality and quantity impacts posed by the Area F expansion, which would require additional withdrawals from the Yellowstone River and potentially negatively affect endangered pallid sturgeon. The plaintiffs also raised the issue of climate change impacts in that lawsuit. U.S. Magistrate Judge Timothy Cavan sided with environmental groups in a February ruling that directed the federal government to redo its analyses.

Cavan said the environmental impact statement listed the expansion’s expected socioeconomic benefits, including continued employment, ongoing royalty payments, and contributions to federal, state and local governments via tax collections, but failed to include a “balanced quantitative analysis of the economic costs of greenhouse gas emissions.” He described the resulting analysis as “skewed” and gave the federal government a year to redo it.


In a March filing, the Interior Department asked for an additional seven months to complete the EIS.

As of press time Wednesday afternoon, Westmoreland was unavailable to provide comment on the lawsuit.

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Amanda Eggert studied print journalism at the University of Montana. Prior to becoming a full-time journalist, Amanda spent four years working with the Forest Service as a wildland firefighter. After leaving the Forest Service in 2014, Amanda worked for Outside magazine as an editorial fellow before joining Outlaw Partners’ staff to lead coverage for Explore Big Sky newspaper and contribute writing and editing to Explore Yellowstone and Mountain Outlaw magazines. Prior to joining Montana Free Press’ staff in 2021 Amanda was a freelance writer, researcher and interviewer. In addition to writing...