Federal officials rejected a company's bid to acquire 167 million tons of coal on public lands in Montana for less than a penny per ton.
The failed sale highlights a continued low demand for coal among utilities, which are turning to cheaper natural gas and renewables like wind and solar to generate electricity.
Emissions from burning coal are a leading driver of climate change, which scientists say is raising sea levels and making weather more extreme.
President Donald Trump has made reviving the coal industry a key part of his agenda to increase U.S. energy production.
Author's summary: US rejects lowball coal bid on public lands.