Five stories from Black Gold Boom, my multimedia series on North Dakota's oil boom, have aired on Marketplace, including one about a mixed-martial arts match in Williston, North Dakota. One fan told me she really liked the violence at these events. "The fighting," she said. "The blood. The broken bones. There's a possibility there's broken bones." Three of the stories are posted below. And there's also a video of the mixed-martial arts match with great pics by Ben Garvin.