For the third time, the U.S. Forest Service has given a green light for the Mountain Valley Pipeline to cross the Jefferson National Forest near the border between West Virginia and Virginia.

It’s a critical link for the 300-mile pipeline, which is a priority for state leaders but is opposed by environmental groups.

Its opponents have been successful in stalling the pipeline. Earlier this month, a federal appeals court voided the West Virginia Department of Environmental Protection’s clean water certification.

Another pipeline opponent: The West Virginia Coal Association. If it is completed, the pipeline would supply natural gas to Duke Energy power plants in North Carolina, at the expense of coal that currently comes from West Virginia.

Efforts by lawmakers, including U.S. Sens. Joe Manchin, D-W.Va., and Shelley Moore Capito, R-W.Va., to speed up the permitting process for the pipeline have not advanced.