According to Reuters, a lawsuit was filed on Wednesday in the US District Court in Washington by the Sierra Club and WildEarth Guardians alleging the federal Bureau of Land Management did not consider the wider impact of selling the leases.
The two groups believe mining and burning coal from the federal leases will result in detrimental environmental impacts, including significant amounts of greenhouse gases emissions when the coal is burned.
The leases are located in the Wyoming portion of the Powder River Basin, a region which produces about 40% of the country’s coal.
According to the news service, the groups are calling for a federal judge to suspend the government's plan to lease and mine coal from the leases until the BLM completes an analysis on the environmental impacts.
It is understood the BLM leases are in close proximity to Arch Coal’s Black Thunder mine and Peabody Energy’s North Antelope Rochelle mine.
Reuters reported BLM had already sold off one of the four leases to Arch Coal, with another of the leases tipped to be sold in mid-May.