An appellate court panel in Denver has dismissed legal challenges by California, New Mexico and a coalition of 16 environmental groups over an Obama-era rule governing associated natural gas flaring and venting on public and tribal lands.

Three judges with the U.S. Court of Appeals for the Tenth Circuit ruled Tuesday that appeals of a district court's decision to stay implementation of the Waste Prevention, Production Subject to Royalties, and Resource Conservation Rule, aka the venting and flaring rule, were moot because the Trump administration has rescinded the rule.

At issue is a ruling by U.S. District Court Judge Scott Skavdahl of the District of Wyoming. Skavdahl ruled in April 2018 that the phase-in provisions of the venting and flaring rule, should be placed on hold to give the Department of Interior's (DOI) Bureau of Land Management (BLM) more time to revise or rescind the rule.

The states and environmental groups urged the Tenth Circuit to reverse Skavdahl's decision, but circuit judges Robert Bacharach, Carlos Lucero and Carolyn McHugh refused.

"We do not see any harm in allowing the district court to decide in the first instance whether the entire case is moot given that the district court is more acquainted with the overall claims and issues," Lucero wrote for the panel in State of Wyoming v. DOI, No. 18-8027.

Environmental groups won a challenge in U.S. District Court for the Northern District of California in February 2018. At the time, Judge William Orrick rejected a BLM proposal to delay enforcement of parts of the rule until January.

The Independent Petroleum Association of America and the Western Energy Alliance filed a lawsuit against the rule in Wyoming district court in November 2016. Montana and Wyoming filed a separate lawsuit, and North Dakota and Texas subsequently joined as petitioners. The two lawsuits were eventually combined.