DENVER, Colorado— Gov. Bill Ritter, who has made promoting renewable energy a cornerstone of his administration, is calling natural gas "a mission-critical fuel."

Ritter spoke at the Colorado Oil and Gas Association's annual conference Thursday in Denver. He told the crowd of industry officials that natural gas production is crucial as the country grapples with climate change and shoots for energy independence.

Ritter and the trade group have been at odds as his administration has promoted stricter oil and gas regulations and a "new energy economy," including trying to attract renewable energy companies to Colorado.

Association spokesman Nate Strauch says the industry was encouraged by Ritter's speech.