FRONTLINE, Marketplace and ProPublica have won a multiplatform award from the Investigative Reporters and Editors for Big Sky, Big Money. The award recognizes outstanding investigative reporting.

Big Sky, Big Money explores how the Supreme Court’s Citizens United decision changed political campaigns in America, starting at its epicenter in Montana. It tracks the inner workings of a dark money group, Western Tradition Partnership, through boxes of documents initially found in a meth house in Colorado.

In their comments about the award, the IRE judges said the project “break(s) down a complicated  subject — campaign finance in the post-Citizens United era — in a simple, entertaining fashion.”

Following the broadcast, a Montana judge ruled that WTP had violated the state’s campaign finance laws. The group’s executive director, Donny Ferguson, resigned, taking a new position working for Rep. Steve Stockman (R-Texas).

A day after the film aired, protesters rallied against the group in Helena, Montana. That evening, the Montana Commissioner on Political Practices, which had until recently been holding the documents, reported a break-in. Nothing was stolen; the documents were in a secure location at the time.

WTP, which operates now under the name American Tradition Partnership, may also be under scrutiny by a federal grand jury, which subpoenaed documents in December that were first disclosed publicly by the FRONTLINE film.

A full list of winners can be found here.

Sarah Childress, Former Series Senior Editor, FRONTLINE