The South Dakota Supreme Court heard arguments on Tuesday, April 17, from opponents and proponents of the Keystone XL pipeline.
In 2015, the Public Utilities Commission accepted TransCanada's certification that it can comply with the conditions of its 2010 permit.
Opponents appealed that certification to the Sixth Circuit Court last year, and now appeals the court's decision to the state's high court.
SDPB's Victoria Wicks has this report.
Credit Victoria Wicks file photo