By some accounts, the fight against the Dakota Access Pipeline now looks unwinnable. Standing Rock became a ghost town last week after police raided and razed the prayer camp that once hosted thousands of water protectors. Earlier this month, the Trump administration fast-tracked approval to build the final section of the pipeline and cancelled the environmental impact statement ordered by President Obama. Construction is nearing completion and oil could flow through the pipeline as early as March 6. For the Standing Rock Sioux Tribe, time is running out — fast.

The Sioux’s best shot at stopping Dakota Access now lies in court. It may be a long shot, but a legal win is still possible, some advocates say.

A legal challenge filed by the tribe on Feb. 14 charges pipeline builder Dakota Access, LLC, and the U.S. Army Corps of Engineers with a range of environmental, cultural, and treaty-based violations. It asks a federal judge to rule on whether the Army Corps broke laws and treaties by allowing construction of the last leg of the pipeline under Lake Oahe, a reservoir along the Missouri River in North Dakota.