The Standing Rock Sioux tribe, who protested the completion of the Dakota Access Pipeline for months, filed a legal challenge to block the completion of the pipeline on Thursday.
David Archambault II, chairman of the tribe, told Reuters Wednesday the tribe was "running out of options, but that doesn't mean that it's over."
President Trump signed an executive order to complete the pipeline last month. An easement to finish the pipeline was granted Wednesday, and drilling has already begun.
BREAKING: Tribe fighting Dakota Access oil pipeline files legal challenge to try to block project's completion.— The Associated Press (@AP) February 9, 2017
Energy Transfer Partners, the pipeline's builder, said drilling had already begun to lay pipe under Lake Oahe. The drilling is expected to take 60 days, plus 23 more days to fill the line, spokeswoman Vicki Granado said.
The specifics on the legal action taken are not clear at this time.
The Associated Press contributed to this report.
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