BISMARCK, N.D. -

Law officers arrested about three dozen Dakota Access oil pipeline protesters in a confrontation that also shut down a state highway.
    
The midday Friday incident began after about 100 protesters confronted crews doing work along the pipeline route where pipe had already been laid. Morton County sheriff's spokeswoman Donnell Hushka says workers were safely evacuated.
    
It happened about 20 miles away from a protest camp where hundreds of pipeline opponents have gathered for months. More than 470 people have been arrested since August.
    
The 1,200-mile pipeline from North Dakota to Illinois is complete except for under the Missouri River in North Dakota. That's been delayed while the Corps of Engineers reviews its permitting.
    
The Standing Rock Sioux and other opponents say the pipeline threatens drinking water and cultural sites.