The U.S. Court of Appeals for the District of Columbia on Wednesday ruled that the Dakota Access Pipeline may stay open, reversing a decision from a lower court that called for the pipeline to be shut down.

In July, U.S. District Court Judge James Boasberg ordered to temporarily shut down the pipeline for 30 days while the U.S. Army Corps of Engineers conducts an additional environmental review of its operations. The pipeline was already subject to a review in 2017 that was expedited by President Trump. 

A three-judge panel said the lower court did not have the “findings necessary” to shut down the pipeline. At the same time, the appeals court did not cancel the additional environmental review of the pipeline.

“Appellants have failed to make a strong showing of likely success on their claims that the district court erred in directing the Corps to prepare an environmental impact statement,” the judges said Wednesday.

The 1,172-mile-long pipeline extends from North Dakota to Illinois and became commercially operational on June 1, 2017. The pipeline drew controversy due to its possible negative impact on the environment and garnered criticism from Native Americans who believe oil spills from the pipeline could contaminate their drinking water. The Standing Rock Sioux Tribe has opposed the pipeline since it was first announced in 2014. 

“We’ve been in this legal battle for four years, and we aren’t giving up this fight,” Standing Rock Sioux Tribe Chairman Mike Faith said in a statement. “As the environmental review process gets underway in the months ahead, we look forward to showing why the Dakota Access Pipeline is too dangerous to operate.”

Trump has endorsed the pipeline as part of his energy independence policy. In 2016, it was revealed that Trump had a financial stake in Energy Transfer Partners, the Texas-based firm behind the pipeline.