Mineta then appointed McCown to become the first acting administrator / CEO and first deputy administrator / COO of the Pipeline and Hazardous Materials Safety Administration (PHMSA). During his tenure he was responsible for oversight of over one million daily shipments of hazardous materials by land, sea, and air including the nation's 2.6 million miles of pipelines. McCown was instrumental in restoring national critical infrastructure following hurricane Katrina and Rita and received the department's highest award (Gold Medal) for his actions while operating under a secretarial designation. He also oversaw the government's initial response to the largest oil spill on Alaska's North Slope and implemented the one call damage prevention program known as "811". While serving as the country's chief energy transportation regulator, McCown was first to raise concerns over the country's aging pipeline infrastructure network but was also avid in his support of pipelines over other transport methods. He has continued to advance safety and has called for tougher standards following gas pipeline incidents in San Bruno, California and Dallas, Texas. He was also one of the first experts to call for the phasing out older rail cars transporting crude oil known as DOT-111 tank cars.