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Thank you for visiting our website. 

RTO PA (formerly Riitters Thompson & Olson) is a full-service accounting firm serving clients throughout the Central Minnesota area, dedicated to providing our clients with professional, personalized services and guidance in a wide range of financial and business needs. We have an office in Little Falls and Pierz.

On this website, you will find information about RTO PA, including our list of services. We have also provided you with online resources to assist in the tax process and financial decision-making. These tools include downloadable tax forms and publications, financial calculators, news and links to other useful sites. Whether you are an individual or business in or around Central Minnesota, RTO PA has years of valuable experience assisting professionals with their accounting needs.

Reminder to everyone that the IRS continues to urge taxpayers to do a Paycheck Checkup as soon as possible to see if they’re having their employer withhold the right amount of tax.

The IRS Withholding Calculator can help taxpayers check their current withholding, determine if they need to adjust it and avoid tax filing surprises next year.



  • Telephone...
  • (320) 632-3646
  • Fax...
  • (320) 632-2502



  • RTO PA
  • 16403 Haven Road
  • Little Falls, MN 56345
  • Telephone...
  • (320) 468-2868
  • Fax...
  • (320) 468-2884



  • RTO PA
  • 407 Main Street
  • Pierz, MN 56364