ONEOK, Inc. Share: Energy & Environment ONEOK, Inc. Visit Website 4501 Coleman St. Suite 101 Bismarck, ND 58503 (701) 751-6005 (701) 751-6007 (fax) About Rep Info Map About Founded in 1906 and headquartered in Tulsa, Oklahoma, ONEOK Partners is the largest independent owner and operator of natural gas gathering and processing facilities in the Williston Basin. Whom to Contact Danette Welsh View Larger Map