An Oklahoma murder mystery has brought tourists to the town of Arcadia for decades. An old gas station has sat along Route 66 for about a century. If you stop by, Sam Gillaspy, who goes by “Mr. Sam,” is happy to share his story about the station's checkered past. Sam says that back in the 1930s, when two brothers owned the station, a salesman stopped by to ask if they wanted to make counterfeit bills. The illegal business took off. "The counterfeiters, they built a little room back there," Mr. Sam explained. "Then they had a table right here and...