BP is one of the largest producers of natural gas in the US Lower 48. Through a series of mergers with Amoco, ARCO, and Vastar Resources, the company has built a vast portfolio of upstream and downstream operations. BP operates in the Mid-Continent, Rocky Mountains, and Gulf Coast regions. BP has historically produced from mature, low-risk assets in the Mid-Continent. In mid-2008, the company acquired positions in two unconventional shale plays, the Fayetteville and Arkoma Woodford, from Chesapeake. These acquisitions introduced much needed long-term growth opportunities in BP's portfolio of mature fields. However, because its Mid-Continent production is overwhelmingly gas, the company has scaled back investment since the downturn in gas prices. In the near term, BP's focus in the Mid-Continent is on the Cleveland tight sand in the Anadarko Basin and Woodford shale in the Arkoma Basin.