# Ketel Thorstenson, LLP Source: https://planprovider.pro/provider/ketel-thorstenson-llp > Founded in 1936, Ketel Thorstenson, LLP is a CPA firm with 126 employees based in Rapid City in western South Dakota, serving clients across the Black Hills… Employee Benefit Plan Auditor Rapid City, SD ## About Ketel Thorstenson, LLP

Founded in 1936, Ketel Thorstenson, LLP is a CPA firm with 126 employees based in Rapid City in western South Dakota, serving clients across the Black Hills region.

The firm provides accounting, tax, and advisory services for businesses and individuals. Its audit work includes retirement plan engagements, with Stephen Schacht listed as a key contact and auditor.

Clients use Ketel Thorstenson for practical support such as tax planning, audit services, and business consulting. The team’s long operating history and in-house mix of audit and tax staff makes it a fit for organizations that want both day-to-day accounting help and formal assurance work from the same firm.

More details are available at https://www.ktllp.cpa/.

Website: [https://www.ktllp.cpa/](https://www.ktllp.cpa/) Founded: 1936 Employees: 126 ## Office Locations - Rapid City, SD ## Accreditations & Certifications - AICPA EBPAQC - AICPA Member ## Audit Statistics (2024) - Total Plans Audited: 35 - Total AUM Audited: $862.0M - 401(k): 35 plans, $862.0M AUM ## Plans Serviced (2025) Largest plans where this firm is listed as a service provider (Schedule C) or IQPA (Schedule H) on the most recent filings (From Form 5500). | Plan|Sponsor|Assets|Participants| | RAPID CITY MEDICAL CENTER 401(K) PLAN|RAPID CITY MEDICAL CENTER, LLP, SD|$75M|437| | RE/SPEC INC. EMPLOYEE 401(K) RETIREMENT PLAN|RE/SPEC INC., SD|$67M|487| | BLACK HILLS FEDERAL CREDIT UNION 401(K) PLAN|BLACK HILLS FEDERAL CREDIT UNION, SD|$60M|372| | BANKWEST 401(K) PLAN|BANKWEST, INC., SD|$59M|357| | SOUTH DAKOTA ASSOCIATIONS OF COMMUNITY-BASED HUMAN SERVICES RETIREMENT PLAN|SOUTH DAKOTA COUNCIL OF COMMUNITY BEHAVIORAL HEA, SD|$53M|1,810| | BLACK HILLS SURGICAL HOSPITAL 401(K) AND PROFIT SHARING PLAN|BLACK HILLS SURGICAL HOSPITAL, LLP, SD|$51M|463| | RE/SPEC INC. EMPLOYEE STOCK OWNERSHIP PLAN|RE/SPEC INC., SD|$45M|568| | RIDDLE'S GROUP, INC. RETIREMENT SAVINGS PLAN|RIDDLE'S GROUP, INC., SD|$40M|538| | HAWKINS ASH CPAS, LLP RETIREMENT PLAN|HAWKINS ASH CPAS, LLP, WI|$34M|215| | BLACK HILLS ORTHOPEDIC AND SPINE CENTER 401(K) PROFIT SHARING PLAN|BLACK HILLS ORTHOPEDIC AND SPINE CENTER, SD|$30M|157| | SECURITY FIRST BANK 401(K) PLAN|SECURITY FIRST BANK, SD|$30M|282| | TAKKION OPS MANAGEMENT LLC 401(K) PLAN|TAKKION OPS MANAGEMENT LLC, WY|$26M|1,621| | COPELAND BUHL & COMPANY, PLLP PROFIT SHARING PLAN|COPELAND BUHL & COMPANY PLLP, MN|$23M|111| | BROSZ ENGINEERING, INC. 401(K) PROFIT SHARING PLAN|BROSZ ENGINEERING, INC., ND|$22M|109| | LLOYD COMPANIES 401(K) PLAN AND TRUST|LLOYD COMPANIES, INC., SD|$20M|353| | BLACK HILLS REGIONAL EYE INSTITUTE 401(K) PLAN AND TRUST|BLACK HILLS REGIONAL EYE INSTITUTE, LLP, SD|$17M|113| | FLOYD'S TRUCK CENTER, INC. 401(K) PLAN|FLOYDS TRUCK CENTER, INC., NE|$15M|227| | MIDWESTERN MECHANICAL, INC. 401(K) PROFIT SHARING PLAN|MIDWESTERN MECHANICAL, INC., SD|$13M|275| | MIDWEST RAILCAR REPAIR RETIREMENT SECURITY PARTNERSHIP PLAN|MIDWEST RAILCAR REPAIR, INC., SD|$11M|144| | MCKIE FORD LINCOLN, INC & AFFILIATES 401(K) PLAN|MCKIE FORD LINCOLN, INC & AFFILIATES, SD|$11M|172| Showing top 20 of 33 plans serviced in 2025. ## Other Employee Benefit Plan Auditors in SD - [ELO Prof LLC](https://planprovider.pro/provider/elo-prof-llc) - Mitchell, SD - [Henjes, Conner & Williams, P.C.](https://planprovider.pro/provider/henjes-conner-and-williams-pc) - Dakota Dunes, SD [View full interactive profile on PlanProvider.Pro](https://planprovider.pro/provider/ketel-thorstenson-llp) © 2026 PlanProvider.Pro