Montana-Dakota Utilities surpasses 50,000 natural gas customers in Black Hills BISMARCK, N.D. – Dec. 28, 2015 – Montana-Dakota Utilities has surpassed 50,000 natural gas customers in the Black Hills Region, a milestone that has been 87 years in the making. The Black Hills Region extends from Belle Fourche through Rapid City. “A big thank you goes out to our customers for