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Leadership Team Bios

Our executive leadership team has more than three decades of experience in leadership and energy, particularly in acquiring, developing, operating and growing natural gas and oil reserves from multiple formations both vertically and horizontally.



Mr. Mullennix attended New Mexico State University with a major in Business Administration. During spring, summer and winter breaks from NMSU, he worked for Four Corners Drilling Company in Farmington, New Mexico as a roughneck on various drilling projects in the San Juan Basin of New Mexico and Colorado.


Prior to graduating NMSU in 1983, Berry formed and owned a construction/remodeling company in Dallas, TX which was purchased by a European company in 1988. In 1989, Mr. Mullennix re-entered the oil and gas industry marketing oil and gas joint ventures for a Dallas based broker/dealer. In mid-1992 he formed Mullennix Consultants, Inc. which acted as an independent consultant and broker to investors and oil companies, consulting on financing (bank, institutional, and private) mergers, acquisitions and investments. He has worked on project financing (including senior debt, equity, VPPs, mezzanine, etc.) from $100M-$500MM. In December 1995, Roy Grossman and Mr. Mullennix formed Mannix Oil Company, Inc., which was an early pioneer of horizontal CBM development. In September 2001, Mannix was sold to Williams Production Company.


In mid 2003 Mr. Mullennix, Mr. Grossman and key former employees, teamed up to form Cannon Energy which was funded by Kayne Anderson. Cannon was sold to form Panther Energy Company, LLC (Panther) in 2005 which is majority owned by the Southern Ute Indian Tribe. Panther has 85 employees and operates in Texas, Oklahoma and Montana. Mr. Mullennix is a member of multiple states’ oil and gas associations including the IPAA (also serving on the Crude Oil Committee), the board of the Oklahoma Independent Petroleum Association (also serving as the Federal Issues Committee Chairman) and the board of the Domestic Energy Producers Alliance (Secretary/Treasurer). Mr. Mullennix also serves on the board of the Harold Hamm Diabetes Center at OU Medical Center.



Mr. Grossman graduated from the University of California with a degree in Engineering and holds a Master’s Degree from the University of Idaho. He has worked in the petroleum industry since 1969, when he worked on rigs in the Santa Barbara Channel for Gulf Production Company, prior to graduating. From 1971-1981, Gulf Oil Corporation employed Mr. Grossman as a Drilling and Operations Engineer.


Over the next few years, he worked for Sun Oil Company, and then left to teach Petroleum Geology at City University of New York and work as a consultant to companies such as Superior Oil and Canadian Hunter Oil Company. In 1984, he was appointed to the board of directors and held the title of Vice President in three public companies traded on the NASDAQ (Jergoil, Black Giant Oil and International Royalty and Oil Company). During his tenure with these companies, Mr. Grossman was responsible for the domestic and international drilling and acquisition programs until the companies were sold in 1988.


In 1989, he formed a private exploration and production company in Oklahoma that grew at an annual rate of more than 40%. In 1995, he participated in the start-up of Mannix Oil Company, Inc. After the sale of Mannix, in 2001 he worked as a consultant for Williams as a post-closing requirement. In 2003, along with Berry Mullennix and Kayne Anderson Energy Fund, he formed Cannon Energy, the predecessor to Panther Energy Company LLC. In 2005, he, Berry Mullennix, a few key employees and the Southern Ute Indian Tribe Growth Fund formed Panther Energy Co.



Mr. Nevins graduated from Brigham Young University in 1985, receiving a Bachelor of Administration degree in Accounting. He later graduated from the University of Tulsa in 1992, receiving a Master of Business Administration. Jeff has over 25 years of accounting, finance, operations and business development experience domestically and internationally at both the business unit and corporate level of the organization.


Jeff began his career with Amoco Production Co. and participated in their “Executive Management Program” and gained valuable experience in all facets of the business. He played a major role relocating and installing a new ERP system for Amoco in 1988 when many of the accounting and finance processes were transferred to Tulsa. After receiving his MBA, Jeff went to work for The Williams Companies. While at Williams, Jeff served in many leadership capacities, including: Vice President of International Business Development, Vice President of Finance, Vice President of Corporate Development and Chief Financial Officer of Williams International. He played a significant role during the Williams restructuring years by selling assets, developing a new strategic focus for the company, creating two different Master Limited Partnerships (MLP’s) and spinning out Williams Exploration Company (WPX). He has served on numerous community boards and currently is the President of the Hispanic American Foundation in Tulsa.



Mr. Stone has over 35 years of experience in domestic and international energy business development, major project and operations management, land management and major A&D transactions. From 2007 to present, Jim has led Panther’s expansive business development effort, establishing, growing and monetizing significant positions in a variety of basins throughout the U.S. He’s negotiated transactions totaling over $1 billion for Panther.


From 1989 to 2006, Jim held a variety of positions with Unocal, working in over 30 foreign countries around the globe.

From 1997 to 2003, Jim spearheaded the development of a large business unit and managed high-profile integrated and cross-border projects in South Asia. He served as President of Unocal Bangladesh, where the company discovered more than 10 trillion cubic feet of natural gas and was the country’s largest foreign investor.


From 2003 to 2006 as Manager of International New Ventures, he led a team of senior geologists, geophysicists and engineers charged with developing and implementing Unocal’s international new ventures and new country entry strategies. Prior to moving into the international arena, Jim managed the Mid-Continent Region land department – Unocal’s largest, comprising a 25-state area.


From 1983 to 1992, he was an independent oil and gas producer in Oklahoma. From 1978 to 1983, Jim held landman and land manager positions with Forest Oil, Regan Petroleum and Harris Minerals/Bunker Exploration. Mr. Stone holds a Juris Doctorate from South Texas College of Law and is a member of the State Bar of Texas. He has a Master’s Degree in Business Administration from Houston Baptist University and a Bachelor of Arts degree in History from the University of Central Oklahoma.



Mr. Blankenship began his oil and gas career in 1987 where he was involved in all aspects of gas compression and measurement in various fields in Texas, Arkansas and Oklahoma. In 1995 he started contract pumping from his home base in Red Oak, Oklahoma, working the Arkoma Basin. In 1997, Mr. Blankenship started working for Mannix Oil Company, Inc. He became the Production Superintendent in 1999 where he managed the pumpers and was involved in the well completions, hookups and well compression.


When Williams purchased Mannix, Mr. Blankenship continued his duties as Production Superintendent for the Arkoma Asset Team. In his last year with Williams, in addition to his regular duties, he oversaw the construction of 57 miles of gas gathering lines of which 18 miles were high pressure DOT lines. He also supervised the setting of 27 compressors during that period of time. With his experience he also brings DOT Certification and HAZWOPER Certification.