About Us

Frontier Rail

Founded and owned by Paul Didelius, the Frontier Rail Group of companies includes six short line railroads operating over 300 track miles plus industrial switching operations in five states. With an industry leading safety record and strong compliance program, Frontier Rail’s experienced management team and approximately 55 employees deliver safe, efficient, and cost effective transportation and other rail services.


Paul Didelius

After finishing a degree in Mechanical Engineering at Case Western Reserve University in Cleveland, OH, Paul worked in management for Union Pacific in Chicago, IL. In 2006, Paul founded Frontier Rail with a leased SD9 locomotive and a single switching contract in Wallula, WA. Nine years later, the Frontier Rail Group of companies includes six short line railroads and rail switching operations in five states – just the beginning.


Robert Didelius

  • Frontier Rail CFO and Director of Operations of Western Region, with the company since January 2012
  • Senior Auditor, SEC practice, Marcum LLP, Los Angeles, CA, 2006 – 2011
  • MA Accountancy, University of Southern California
  • BA Economics, Northwestern University

Katie Inouye, CPA

Katie Inouye, CPA joined Frontier Rail as Accounting Manager and Controller in 2016. Before coming aboard, Katie was an Audit and Tax Manager at a national public accounting firm where she developed expertise in cost analysis, financial projections, and construction accounting. Outside of work, Katie enjoys spending time with her two daughters and running obstacle courses.