RAPID CITY, S.D. – Ketel Thorstenson, LLP (KT), the largest accounting firm in the Black Hills region, is proud to announce a strategic merger, effective January 1st, 2026, with respected Casper, WY based accounting firm, Grooms & Harkins, P.C. (G&H). This marks a significant milestone in both firms’ commitment to excellence, innovation, and regional growth.

“We’re bringing the best of both firms together,” says Nina Braun, CEO and Partner at KT. “Combining our strengths to offer broader services, deeper expertise, and greater value to our clients across South Dakota and Wyoming.”

This merger brings together two firms with deep roots in their communities and a shared dedication to client service. As part of the agreement, current stakeholders from G&H will be admitted as Partners at KT, ensuring continuity of leadership and client relationships while expanding the firm’s reach and capabilities.

“Our clients will benefit from KT’s comprehensive accounting and advisory services,” stated Nic Grooms, managing shareholder at G&H. “Our shared expertise in the construction, agriculture, and nonprofit industries made this merger an ideal fit for our clients and staff.”

Both firms share a strong commitment to community engagement, professional development, and client-centered service. KT’s longstanding presence in Rapid City, Spearfish, and Gillette is now complemented by a strengthened footprint in Casper.

The merger will be effective January 1st, 2026, with integration efforts already underway. KT will continue to operate under its existing name, with G&H’s Casper office adopting KT branding and systems.

G&H clients can expect uninterrupted service and enhanced resources as the firms unite under a shared mission to elevate their clients’ financial standing, optimize their business practices, and give them the confidence to plan for the future.