Before protest conflict, pipeline builder found artifacts

The company building a controversial oil pipeline north of the Standing Rock Sioux Reservation failed to immediately notify regulators after finding four stone cairns and other artifacts during construction in Morton County as tensions grew among pipeline opponents, documents show. Dakota Access, a subsidiary of Dallas-based Energy Transfer Partners, waited at least 10 days to notify the North Dakota Public Service Commission about an unanticipated discovery in mid-October, a potential violation of the state permit for construction. The company formally notified regulators Oct. 27, making the report a public record for the first time, the same day hundreds of law officers evicted protesters blocking the pipeline’s route on private land, leading to 141 arrests.