Tengasco, Inc., together with its subsidiaries, explores for and produces oil and natural gas in the United States. It primarily holds interests in the oil and gas properties located in Kansas. As of December 31, 2018, the company had 174 producing oil wells, 20 shut-in wells, and 38 active disposal wells. The company was formerly known as Onasco Companies, Inc. and changed its name to Tengasco, Inc. in 1995. Tengasco, Inc. was founded in 1916 and is headquartered in Greenwood Village, Colorado.