John Callon began his career in the oil and gas business in 1950. He built Callon Petroleum into a publicly traded Nyse-listed company with a market capitalisation of $350 million. He retired as chief executive officer in 1997.
"He was a remarkable person who will be missed by all of us," said Fred Callon, the company chairman, chief executive officer, and John Callon's nephew.
"He
