Tulsa, Oklahoma

===Energy industry's legacy and resurgence===
The [[United States Oil and Gas Association]] was founded in Tulsa on October 13, 1917.<ref>{{cite web|url=https://www.usoga.org/en/about_us/history/|title=A Brief History|publisher=usoga.org|access-date=May 26, 2014|archive-date=May 28, 2014|archive-url=https://web.archive.org/web/20140528010746/https://www.usoga.org/en/about_us/history/|url-status=dead}}</ref> Over the city's history many large oil companies have been headquartered in the city, including Warren Petroleum (which merged with [[Gulf Oil]] in what was then the largest merger in the energy industry), [[Skelly Oil]], [[Getty Oil]] and [[CITGO]]. In addition, [[ConocoPhillips]] was headquartered in nearby [[Bartlesville]]. Industry consolidation and increased offshore drilling threatened Tulsa's status as an oil capital, but new drilling techniques and the rise of natural gas have buoyed the growth of the city's energy sector.

Today, Tulsa is again home to the headquarters of many international oil- and gas-related companies, including [[Williams Companies]], [[ONE Gas]], [[Syntroleum]], [[ONEOK]], [[Laredo Petroleum]], Samson Resources, [[Helmerich & Payne]], [[Magellan Midstream Partners]], and Excel Energy.