Leadership Team

Board of Directors

Executive Leadership Team

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 our general partner. 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.


Dan Carlson


Daniel L. Carlson, P.E., joined Montana Renewables in April 2022 as Vice President Strategy and Development. Dan has over 40 years of industry experience. He is responsible for identifying and developing commercial growth and operational enhancements for feedstocks, products and physical assets for Montana Renewables. He previously held roles including Process Engineer, Project Manager, Process Engineering Manager, Technical Manager, Operations Manager, Vice President – Refinery Manager, and Vice President – Planning and Optimization for Tosco, Ultramar Diamond Shamrock, Tesoro Corporation and Andeavor Corporation. Dan earned his BS in Chemical Engineering from the University of California, Berkeley, his MBA from Saint Mary’s College of California, and is a registered Professional Engineering in California.


Ron Colwell


Over 27 years of experience in the petroleum refining industry. Ron has served as the Montana Renewables General Manager since its inception. Ron joined the facility in 2008 as Engineering Manager leading the Low Sulfur Fuels Expansion Project while continuing to grow and develop the engineering department. Ron joined Process Engineering Associates as a full partner in 2004 developing a presence in the refining industry. Prior experience includes roles as Operations Manager, Engineering Manager, Sr. Process Engineer, and Process Engineer with ExxonMobil, Total, and Amoco Production Company. Ron graduated in 1994 with a BS in Chemical Engineering from Colorado State University after serving 4 years in the US Navy.


Michael Wojciechowski


Michael Wojciechowski, or Wojo to his friends and colleagues, joined Calumet in 2018 as Director of Strategy and Growth with over 24 years of experience in the industry. He assumed his current role as Commercial and Compliance Director for Montana Renewables since its inception.  He is responsible for directing the value optimization for the feedstock supply and product offtake arrangements, as well as assuring compliance with the various jurisdictions and programs for renewable fuels.  He previously held roles in Process Engineering, Lab Operations, Optimization Planning, Market Analysis, and Management with Wood Mackenzie, Merrill Lynch Commodities, Tesoro Corporation, and Mustang Engineering.  Wojo earned his BS in Chemical Engineering from Texas A&M University and an MBA from the Kelley School at Indiana University.


Trent Weatherly


Trent Weatherly joined Montana Renewables in the spring of 2022 and handles all inbound feedstock procurement for the Great Falls plant. Trent comes from the large agriculture sales and trading company, Cargill Inc where he spent the last 14.5 years in various commodity trading roles with the last 5-plus years managing the trading book for the beef rendering products division for North America. Trent has a solid background in logistics, truck and rail, and a deep understanding of the tallow and oils markets in the US. Trent earned his BS in Animal Science – Ag Production from the University of Missouri-Columbia.

Derek Roesener


Derek Roesener joined Calumet in 2014 and has 28 years of experience in finance and accounting. He assumed his current role as Director of Finance – Montana Renewables in 2021. In this role, he is responsible for directing and coordinating the financial functions of MRL. Prior to this role at Calumet, Derek was Director of Strategy where he coordinated several divesture and acquisition transitions at Calumet. Derek has served in various industry roles as CFO, Director of Finance, Assistant Treasurer, Business Unit Controller and Tax Manager for Magnatech Manufacturing, Brightpoint North America and Delco Remy after working 6 years at Arthur Andersen. Derek earned his B.S. degree from Cornell University and M.S. degree from the Krannert School of Management at Purdue University.

Leading the Energy Transformation

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