Leadership Team


Scott Peterson

Chief Executive Officer

In addition to his accounting and financial background, Scott provides the Interstates Companies a strategic planning focus and long-term planning skills.

Scott is a certified public accountant, a certified internal auditor, and holds degrees in accounting and business administration from the University of South Dakota.

Prior to joining the Interstates team in 1995, Scott was a public accountant with KPMG and held several positions with Valero Energy, a Fortune 500 firm. He also serves as president of the Harbor Group, Interstates holding group and vehicle for future growth.

Larry Den Herder

Chairman, Interstates Companies

Larry’s experience in the industry and his partnership in the Interstates Companies spans over 40 years.

Larry has an engineering degree from the University of South Dakota and was the operational leader of the Interstates group for most of his career.

At present, he serves as Chairman of the Board.


Chief Financial Officer

Catherine, a CPA, joined Interstates in 2014. As Chief Financial Officer, she oversees Accounting and Marketing functions.

She began her career with Interstates as an Accountant and Executive Assistant but has since spent most of her career with DuPont Pioneer. Starting as Financial Analyst, she advanced into larger leadership roles including Finance Manager, Sr. Marketing Manager and most recently, Commercial Unit Lead with responsibility for sales, services, marketing and supply chain functions.

Dave Crumrine

Interstates Construction Services

Prior to joining Interstates in 1998, Dave worked extensively in construction management and as a general contractor for a large firm.

He is a registered professional civil engineer and holds degrees from South Dakota School of Mines in Civil Engineering/Construction Management and a Masters in Business Administration (MBA) from Western Michigan University.

Dave is a dynamic thinker, servant leader, and people developer.

Doug Post

Interstates Engineering

Doug joined the Interstates group in 1994 after earning his Master’s degree in electrical engineering from Iowa State University.

During his college years at Dordt College (BSEE), Doug worked at Interstates, as well. He is a licensed professional engineer in many states and has grown the company quickly since its inception as a distinct business unit in 1999.

With his leadership team, Doug has authored an Envisioned Future for Interstates Engineering, which includes expansion of engineering services.

Jack Woelber

Interstates Control Systems

When Interstates Controls was established in 1996, Jack was a natural choice as company president.

His background in computer programming and his leadership skills provide a perfect blend of technical and people expertise to lead and grow Interstates Control Systems.

Jack holds degrees in computer programming from Western Iowa Technical College and in business administration from Bellevue University.