A prayer walk on Highway 1806 north of Cannon Ball was held on Thursday to honor the Oceti Sakowin protest camp and the first anniversary of the mandatory evacuation of hundreds of people occupying the camp from federal land maintained the the U.S. Army Corps of Engineers. The prayer walk, which will conclude in Mandan after four days, ended on Thursday at the Backwater Bridge. The bridge was the center of controversy during the months-long clash between law enforcement and the thousands of people protesting the construction of the Dakota Access oil pipeline on sacred lands and under the Missouri River upstream from the community of Fort Yates.