The company’s filing indicated it had, as of the end of the year, nearly $929 million in assets and almost $635 million in total debts.

In its announcement, the company said its mining operations would continue as normal as it moves through the bankruptcy process. But the filing represents the latest concerning episode for coal, which has been one of the main drivers of the state’s economy, along with oil and natural gas.

Friday’s announcement comes only days after Gov. Mark Gordon said he was optimistic about coal’s future. In a statement after the filing, the governor said coal is an integral part of the nation’s and the world’s energy portfolio and will remain so for years.

“That is a fact,” Gordon said. “The proof is in the global energy patterns from last year. I believe we need to find solutions that support coal energy and address climate change. This news about Cloud Peak reinforces why I have advocated so strongly to innovate and advance the conversation about coal energy beyond polarized political rhetoric.”

Powder River producer