The former head of an oil and gas company in Fort Worth pleaded guilty Tuesday to one count of mail fraud in connection with a federal investigation.

James O. Retz previously headed Big Rock Ranches Inc. in Fort Worth and faces a sentence of up to 20 years in prison and a fine of up to $250,000 along with restitution for victims of his investment scheme.

Mr. Retz allegedly sold interests in a variety of oil wells in Texas and Wyoming, but the wells either didn’t exist or the entities doing the drilling weren’t licensed by regulators, according to U.S. Attorney Richard Roper.

Mr. Retz sent out misleading and false statements to investors as part of his scheme. He’ll be sentenced Sept. 2.