Huddleston worked for Huddleston & Co., Inc. during summers 1972-1978 as engineering assistant and roustabout. Since 1980 have practiced primarily as a reservoir engineer, providing reservoir and economic evaluations for the petroleum industry and financial institutions. Successful transactions have resulted in acquisitions, financing arrangements, and public offerings totaling in excess of $900 million. Reserve reports are prepared on a continuing basis for public reporting, financing, budgeting, litigation support, and/or evaluation of investment performance. Appointed President of Huddleston & Co., Inc., in February 1989, and Peter Paul Petroleum Company in January 1999. Appointed Chairman of the Board of Continental Operating Company in 1993. Huddleston & Co., Inc., provides petroleum engineering consulting services for over 150 oil and gas companies, gas transmission companies, banks, and other financial institutions. Foreign projects have included Canada, South and Central America, Africa, Australia, China, Kuwait, Indonesia, the North Sea, and the Commonwealth of Independent States (formerly the Soviet Union). Peter Paul Petroleum Company is a privately held entity, which manages joint venture and partnership interests in over 2,000 producing properties. Continental Operating Company is a privately held oil and gas operating company which operates more than 400 wells located in Arkansas, California, Kansas, Louisiana, North Dakota, Oklahoma, Texas, and Wyoming.

Huddleston lectured at Texas A&M University for an industry seminar and to senior petroleum engineering students on a number of petroleum related subjects including market value determination for oil and gas properties, risk analysis, and financing of petroleum related projects. Presented a seminar pertaining to reservoir evaluation techniques to the Oil and Gas Ministry of Guatemala. Presented papers pertaining to petroleum investment and financing vehicles and reserve classification definitions to the Society of Petroleum Engineers. Composed papers relating to the Natural Gas Policy Act of 1978 and Reserve Recognition Accounting.

Huddleston is a Registered Professional Engineer (Texas No. 57166) and a member of the Society of Petroleum Engineers, Pi Epsilon Tau (Honor Society), Texas A&M University Petroleum Engineering Advisory Board, and Petroleum Club of Houston Board of Directors.