We are a publicly traded Delaware limited partnership formed by Diamondback to own and acquire mineral and royalty interests in oil and natural gas properties primarily in the Permian Basin. Since May 10, 2018, we have been treated as a corporation for U.S. federal income tax purposes.
Our primary business objective is to provide an attractive return to our unitholders by focusing on business results, generating robust free cash flow, reducing debt and protecting our balance sheet, while maintaining a best-in-class cost structure. Our initial assets consisted of mineral interests in oil and natural gas properties in the Permian Basin in West Texas, substantially all of which are leased to working interest owners who bear the costs of operation and development. Diamondback contributed these assets to us upon the closing of our IPO on June 23, 2014.
Like Diamondback, we are currently focused primarily on oil and natural gas properties in the Permian Basin, which is one of the oldest and most prolific producing basins in North America. The Permian Basin, which consists of approximately 75,000 square miles centered around Midland, Texas, has been a significant source of oil production since the 1920s. The Permian Basin is known to have a number of zones of oil and natural gas bearing rock throughout.