Friday’s announcement that the U.S. Supreme Court will hear a legal battle between energy pipeline builders and environmental activists next year could poke a hole in the growing effort to halt natural gas pipeline infrastructure around the country.

In 2017, the federal government approved the Atlantic Coast Pipeline project and the neighboring Mountain Valley Pipeline, designed to carry natural gas through West Virginia, up over the continental divide and down into the large population centers in Virginia and North Carolina.

According to the consortium owners of the Atlantic Coast Pipeline, the project will save $377 million in energy costs and raise $28 million in local tax revenue annually for consumers and businesses in Virginia and North Carolina. The natural gas will likely shutter several coal plants in the region, dramatically cutting carbon emissions from the region’s electricity sector.

But the 4th Circuit Court of Appeals late last year halted construction, arguing that the Forest Service did not have the authority to permit pipelines across the Appalachian Trail, a 2,200 mile walking trail from Georgia to Maine owned by the National Park Service.

Writing for the court, Appellate Judge Stephanie Thacker said that the Forest Service had “abdicated its responsibility to preserve national forest resources” and invoked Dr. Seuss by quoting from The Lorax: “We trust the United States Forest Service to ‘speak for the trees, for the trees have no tongues.’”

An appeal to emotion may not be the strongest argument that Judge Thacker could have made in a legal brief. Given the Supreme Court’s current 5-4 anti-administrative state leanings and dislike for “living constitution” arguments, the Circuit Court opinion may be at risk.

Pipeline supporters got an assist from the Trump administration when U.S. Solicitor General Noel Francisco argued that the appellate court decision “has effectively erected a 2,200-mile barrier severing the eastern seaboard from oil and gas sources west of the Appalachian Trail.”

The pipeline consortium noted that more than 50 pipelines already cross under the trail, but all of them have been sited over private or state land, or the right-of-way existed before ownership of the Trail was given to the Park Service in 1968. The Atlantic Coast Pipeline crossing would tunnel 600 feet underground, and the Appalachian Trail’s Park Service easement is 100 yards wide, but this is a question of whether the Forest Service has the authority to site the pipeline.

A favorable decision for pipeline developers by the Supreme Court would still leave pipeline builders some work to do as ordered by the 4th Circuit. The Forest Service must redo its environmental analysis of the pipeline route, and half a dozen permits still need to be acquired.