Meet our Staff

Cynthia Lynn - President

 Mrs. Lynn is an established entrepreneur having launched Thunderhead Testing, LLC, in 2000 as a platform from which to provide data management services for the Pavement Test Track facility of the National Center of Asphalt Technology at Auburn University. A respected authority in asphalt technology, mixture design and testing, she currently serves as president of the firm. Mrs. Lynn’s areas of technical competence include aggregate and asphalt testing. Past and current research engagements include Majeska & Associates, MeadWestvaco Corp., and Oklahoma State University.
Prior to forming Thunderhead, Mrs. Lynn held various technical positions with Pavement Technology, Inc., Atlanta Testing and Engineering, and the National Center for Asphalt Technology at Auburn University where she earned her M.S.in Civil Engineering in 1996. Her published research accomplishments include evaluation of steel and chrome slag aggregates for use in bituminous mixtures and characterization of aggregate materials for use in bituminous mixtures. She also holds B.S. degrees in Civil Engineering and Engineering Science from Tennessee Technological University (1993) and David Lipscomb University (1991) respectively. 

Todd A. Lynn, P.E. Ph.D. - Principal

 Dr. Todd Lynn is a respected authority in asphalt technology, mixture design and testing. He currently directs and manages the technical operations of Thunderhead Testing, LLC, a construction materials design and testing firm that his wife founded in 2000. Dr. Lynn’s areas of competence include aggregate and asphalt testing, asphalt mixture design development, research and product development of asphalt systems including green technologies such as warm-mix asphalt, reclaimed asphalt pavement and asphalt shingles. Past and current research engagements include Majeska & Associates, MeadWestvaco Corp., and Oklahoma State University. He also provides consultation and training services to national and international companies. Prior to joining Thunderhead full-time in 2010, Dr. Lynn held various technical positions with Oldcastle Materials, SemMaterials, APAC, and the National Center for Asphalt Technology at Auburn University where he earned his Ph.D. in 2002. His published research accomplishments include characterization of modified asphalts and development of a mix design procedure for SMA mixtures. While with APAC, he was associated with numerous paving projects including the construction of the Kansas Speedway. 

Patsy Rorex - CFO

 Mrs. Rorex is currently the Chief Financial Officer of Thunderhead Testing, LLC. She has over 30 years of experience in business administration, accounting and finance. Prior to joining Thunderhead as CFO, Mrs. Rorex held various finance and management positions with Hembree-Rorex Insurance and Conway-Rorex Property Management companies. Mrs. Rorex received her B.A.from David Lipscomb University in 1966. 

Lincoln Beard

 Lincoln has been a lab technician for Thunderhead Testing since September 2012. Lincoln grew up in central Louisiana and after graduating high school attended Louisiana Tech University. He graduated in Spring 2012 with a Bachelor's degree in Industruial Engineering. While in college he participated in projects for Procter and Gamble and Lockheed Martin. In October 2012 Lincoln earned his Aggregate Certification from Oklahoma Department of Transportation. 

Darryl Harvey

 Darryl began his career in construction materials testing with Thunderhead in January 2013. He has an extensive background in logging and sawmill operations producing a variety of wood products. His capabilities also include heavy equipment operation. An avid outdoorsman, Darryl is also an accomplished taxidermist. Darryl holds OKDOT certification for Materials Sampling and Testing. He has quickly become proficient in field construction materials testing involving aggregate, concrete and asphalt. In the lab, he has experience with both hot and warm mix asphalt technologies. His role at Thunderhead also includes that of equipment manager and maintenance of the firm’s vehicle fleet.