Practice History & Experience

Solutions, CPAs PC is a local full-service accounting, auditing, and tax preparation firm of certified public accountants providing services to private and public clients in eastern Oregon. Solutions is a successor organization to Oster and Arntz, a partnership of Arlie W. Oster and James K. Arntz. Mr. Oster founded the firm in 1963 and operated under four other partnerships before forming Oster and Arntz in1989. The corporation was formed on June 1, 1992 as Oster Professional Group, CPAs (OPG) and was the immediate successor organization to the above referenced Oster and Arntz partnership. On January 1, 1993, Robert M. Armstrong and George W. Wilber acquired 100 percent of all outstanding shares of stock of the corporation, one half each.

On January 1, 2014, the John Day and Burns offices each organized as separate corporations (OPGCPA, PC and GW Wilbur & Associates, respectively) and continued to operate as partners of Oster Professional Group, CPAs LLP through December 2018.


January 1, 2018 the two office corporations entered into an agreement whereby on January 1, 2019, the Burns office would obtain sole use of the Oster name. As a result of this agreement the John Day office renamed their corporations from OPGCPA, PC to Solutions,


CPAs PC. The shareholders before and after the name change included Robert Armstrong, Jessica Knowles, Mitch Saul, Anna Bass and Amy Walker.

As of January 1, 2019, Mr. Saul, Ms. Walker, and Ms. Bass acquired the outstanding shares owned by Mr. Armstrong and Ms. Knowles. Mr. Armstrong will continue to work for the company for several more years and serve in an advisory capacity. Currently the ownership of the firm is estimated as follows: Mr. Saul 40%, Ms. Walker 35% and Ms. Bass 25%.

Mitch Saul

Managing partner

Amy Walker


Anna Bass


Harmony Piazza


Carli Bremner

Staff accountant

Chandra Holliday


Bob Armstrong


Lauri Armstrong

Office Manager

melissA Finlayson

administrative assistant


Jeff Pass

Auditor/Tax Preparer

Clayton Ensign

Auditor/Tax Preparer