An investigation into EarthRights International — an environmental advocacy organization behind a high-profile climate lawsuit in Colorado — reveals a laundry list of wealthy progressive donors.

The County and City of Boulder, along with San Miguel County, Colo., are suing ExxonMobil and Suncor, claiming the two companies have done damage to the environment and contributed to climate change, the state entities announced April 20. The plaintiffs are citing “public nuisance” laws as the grounds for their case. Another notable detail: EarthRights International will be providing pro bono legal support for the lawsuit.

ERI, a Washington, D.C., based nonprofit group, works to sue energy companies around the country for alleged abuses to the environment. While the organization has remained mostly under the radar among the endless number of environmental groups in the U.S., a Thursday report by Energy in Depth reveals them to be connected and funded by well-known names in the progressive donor world.

Lara Johnson is a sitting board member of ERI and the development manager for Rocky Mountain Institute, a group that has received millions in funding from California billionaire Tom Steyer, a hedge fund manager-turned Democrat mega-donor. Steyer, of course, has obtained notoriety for shelling out his fortune in an effort to impeach President Donald Trump and unseat Republican lawmakers.

Johnson’s position at ERI also connects the group to liberal billionaire George Soros by way of the Open Society Foundation, where she previously served as the organization’s regional coordinator. Soros founded and finances the Open Society Foundation — an international organization behind the origins of the #ExonnKnew campaign. OSF, in fact, donates hundreds of thousands of dollars to ERI annually.

“It’s amazing that ERI has largely flown under the radar for so long,” contributor Specer Walrath wrote in his Thursday Energy in Depth report. “The group has deep ties to the legal activists and wealthy donors who are executing a coordinated and well-funded campaign against the energy industry. These connections raise a number of unanswered questions; and as the litigation continues, it’s likely that there will be even more sunlight on EarthRights International.”

ERI will provide pro bono work for the climate lawsuit alongside Niskanen Center, another D.C.-based nonprofit that takes in hundreds of thousands in donations from progressive organizations.

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This article originally appeared in The Daily Caller