daily · Climate Policy

Seventeen groups challenge Montana PSC climate decision; lawsuit is not a ruling

Earthjustice says the groups filed on October 15 after the regulator rejected their 2024 petition. Their constitutional and ratepayer-cost arguments remain allegations.

By Greener Numbers Editorial Team · Published October 15, 2026 · Updated 10/15/2026

Earthjustice said on October 15 that 17 organizations filed a lawsuit against the Montana Public Service Commission over its rejection of a petition asking the regulator to recognize a constitutional duty to consider climate change in utility decisions.

The announcement identifies healthcare, youth, clean-energy and climate organizations among the plaintiffs. Earthjustice and the Western Environmental Law Center say they represent the groups.

According to the plaintiffs' announcement, the petition was filed in February 2024, a public hearing took place in April 2024, and the commission resolved the petition on September 15, 2026. The lawsuit challenges that later decision.

The groups argue that the commission should account for climate-related costs and risks when regulating gas and electric utilities. Those are the plaintiffs' legal arguments, not findings made by a court in this new case.

The announcement points to NorthWestern Energy's Yellowstone County Generating Station in Laurel, described as a 175-megawatt methane-gas plant, as an example in its ratepayer-risk argument. It does not establish that the new lawsuit has changed approved rates or stopped the plant.

The filing should be distinguished from an outcome: the source reports a legal challenge and the relief the groups seek. It does not report a new judgment compelling the commission to adopt their position or quantify savings for individual customers.

Official source: earthjustice.org ↗