Board of Directors 

Leadership Team

Board of Directors

Board of Directors

Bruce Fleming

Bruce A. Fleming has served as Executive Vice President — Montana Renewables & Corporate Development of our general partner since February 2021. From March 2016 until the appointment to his current position, Mr. Fleming served as Executive Vice President – Strategy & Growth of Calumet. Prior to joining the Company, Mr. Fleming served as the Vice President of Mergers & Acquisitions at Tesoro Corporation and as an officer of Tesoro Companies Inc. since 2004. From 1997 through 2004, Mr. Fleming served as Managing Director of Hong Kong-based Orient Refining Ltd., and from 1981 through 1996 he held senior operations, business development and planning roles with Amoco Oil and Amoco Corporation where he was most recently Vice President of China business development. Mr. Fleming earned a Ph.D. in chemical engineering from Princeton University and a B.S. in chemical engineering from the University of Delaware. He is a member of the Board of M&A Standards. Mr. Fleming’s expertise is in chemical engineering, refining, strategic growth, mergers and acquisitions, and renewable fuels.


Steve Mawer

Stephen Mawer has served as Chairman and our general partner since May 2022, and has served as a board member since March 2016. He is also Chairman of ClimeCo Corporation, an environmental commodities development and management company and a member of the Board of Directors of Zenith Energy Management, a midstream company. Mr. Mawer led Calumet as CEO from April 2020 to May 2022. He retired as president of Koch Supply & Trading in 2014 following a 27-year career in commodities trading, risk management and refining operations. While at Koch, Mr. Mawer led global commodities trading and served as a senior member of the Koch Industries management team. Mr. Mawer holds Bachelor’s and Master’s degrees in chemical engineering from the University of Cambridge, England. Mr. Mawer brings extensive knowledge of petroleum markets, refining economics, supply/marketing optimization and risk management.


    Todd Borgmann

    Todd Borgmann has served as Chief Executive Officer of our general partner since May 2022. Prior to that, he was executive vice president – chief financial officer of our general partner since February 2021. Mr. Borgmann has fifteen years of experience with Calumet, serving the Company across a diverse set of management roles. For the five years preceding the appointment to his current position, Mr. Borgmann served as Senior Vice President – Chief Financial Officer, Senior Vice President – Interim Chief Financial Officer, and Vice President of Supply & Trading. Mr. Borgmann has also served as Calumet’s Vice President of Business Development and Director of the Partnership’s White Oils and Petroleum sales. Mr. Borgmann earned a Bachelor of Science in Industrial Engineering from Purdue University and a Masters of Business Administration from the University of Notre Dame. Mr. Borgmann’s brings extensive expertise in petroleum markets, refining operations and risk management.


    Jeff Luse

    Jeff Luse joined Warburg Pincus in 2015 and focuses on energy transition and sustainability investments. Previously, he worked at Vestar Capital Partners where he focused on financial services and diversified industrial investments. Prior to that, he worked in the Financial Institutions Group at Credit Suisse. He is a Director of ClimeCo, Gradiant Corporation, Ridge Runner Resources, Viridi Energy and Zenith Energy. Jeff also works with Eco Material Technologies and Wildfire Energy. He received a BA magna cum laude in Economics from Princeton University and an MBA from Harvard Business School.


    Leading the Energy Transformation

    Montana Renewables, LLC is a subsidiary of Calumet Specialty Products Partners, L.P. Visit for more information.