It was sent to Jewell on Monday and signed by 21 environmental, health and consumer rights organizations.

The letter calls for an immediate moratorium on new leases in the basin, located in both Montana and Wyoming, until the federal government reviews the program.

The groups, which include the Sierra Club and Greenpeace, claim that approving new coal leases in the PRB would be “undermining President Obama’s commitment to address climate change”

Also citing recent federal investigations into allegations of companies not paying proper royalties, the groups say that the government needs to make sure it continues to manage exports and leases “in the best interests of the nation”

The Government Accountability Office and the Department of Interior’s inspector general are investigating the federal coal leasing program at the request of Congress.

“Not surprisingly, these new developments have cast doubt on whether Department of Interior and Bureau of Land Management are managing this resource in the best interests of the nation,” the groups claimed in the letter.

“The Department of Interior must ensure that coal companies do not cheat US taxpayers, existing mines do not endanger our air, water and wildlife and are properly reclaimed and the greenhouse gas emissions from federal coal leases do not conflict with the administration’s stated commitment to reduce the country’s contribution to climate change.

“With so much at stake, we urge you to suspend auctions of taxpayer-owned coal and establish a moratorium on new coal leasing in the Powder River Basin.

“A comprehensive review of the federal coal leasing program is needed to ensure that the public has a clear answer to how the federal coal leasing program will be reformed to serve the public interest.”

Outdoor clothing group REI chief executive officer Jewell was confirmed as the nation’s interior secretary last week in an 87:11 vote in the US Senate.