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Our new Client Portal allows you to securely share files with KTLLP. Use this link to access FileDrop, E-Payroll, & Time Clocks:

KTLLP Client Portal

For full feature access or if you have questions, please contact This email address is being protected from spambots. You need JavaScript enabled to view it..


Work for the best - work with the best! Our firm is currently hiring...
Find out what makes Ketel Thorstenson, LLP stand out from the rest:

Meet the Firm

Events & News


Ketel Thorstenson, LLP (KTLLP) is a Rapid City, South Dakota accounting practice with nearly eight decades of experience in providing professional tax, audit, accounting, and consulting services.

Take a look at the 2014-2015 Tax Guide. Click here for pdf version.

Affordable Care Act Form Pricing. Click here for pdf version.

If you would like to pay an invoice online with a credit card click on the Pay Now button.

Pay Now button


Thank you for visiting the KTLLP website:

Existing Clients

Existing clients are invited and encouraged to use the KTLLP Client Portal. The Client Portal is perfect for sharing files with Ketel Thorstenson employees or accessing E-Payroll and TimeClocks. Please Contact Us with any questions and/or concerns.


If this is your first time here, allow us to point you in the right direction. Most first-time visitors will start by discovering what Ketel Thorstenson, as a leading Black Hills accounting firm, is all about. By following the About Us link, you’ll gain privilege to Company History, Company Mission & Culture, Company Affiliations, and much more….but this is just the beginning. Touch on the “personal” side of our accounting practice—meet our Partners and Managers, check out our western South Dakota Locations, and see for yourself how we remain an active partner in the Black Hills area with Community Involvement.

Read More…

What brings you to us today? Are you seeking out a CPA to provide a specific service? Or are you searching for a professional tax and accounting resource for your specific business or industry? Either way, we’ve got you covered. Your next step? Start browsing here...


Ketel Thorstenson, LLP offers an extensive menu of professional services, including: tax preparation, tax planning, audit services, bookkeeping, payroll services, business valuation, estate planning, and MORE.


Knowing your industry—it’s important to you, and it’s important to us, as well. We’ve fine-tuned a variety of niche services for clients engaged in the following industries/businesses: agriculture/ranch, construction, hospitality, non-profit, tribal, cities and schools, financial institutions, realestate, medical, and MORE.

If you’re unsure or not finding what you’re looking for, contact our main office today. Our CPAs and administrative staff will be happy to assist you. Contact Us.

Who Is Your Certified Public Accountant (CPA)?

Education and credentials are important—but so is the relationship that is built between a CPA and his/her client. Ketel Thorstenson CPAs are:

EDUCATED | our partners, managers, and tax/audit staff hold Bachelor’s and Master’s level degrees in Accounting and related fields from accredited institutions from all over the U.S.

CERTIFIED | the American Institute of CPAs (AICPA) protects public interest by licensing only the most qualified, experienced, and ethical accountants as “Certified Public Accountants.” At KTLLP, we protect our clients with the same standards.

PROFESSIONAL | what does “nearly eight decades” of professional service mean to you? To us, it means that our clients’ needs are fully and consistently met; that our strong reputation has been built on a long-lasting and unfailing model for client satisfaction.

PARTNERS & FRIENDS | your CPA should be more than just your CPA. He or she knows you by name, understands the needs of your business and industry, and considers your mutual relationship a partnership; oftentimes, a friendship. Most importantly, your Ketel Thorstenson CPA is someone you can trust. This is what we mean by “Friends for Life.”

Meet the CPAs at Ketel Thorstenson, LLP—Partners and Managers—and contact us today to begin a successful and sustaining partnership.

Ketel Thorstenson, LLP

About Us | Careers | Events & News | Services | Affiliated Companies | Industries

810 Quincy Street | Rapid City, SD 57701 | Tel (605) 342-5630 | Fax (605) 342-2172
123 E. Jackson Boulevard, Suite 2 | Spearfish, SD 57783 | Tel (605) 642-7676 | Fax (605) 642-2616
609 Mt. Rushmore Road | Custer, SD 57730 | (605) 673-3220 | Fax (605) 673-3114
603 Main St. | PO Box 608 | Williston, ND 58802 | Tel (701) 774-3836 | Fax (701) 774-0672
Website: www.ktllp.com • Email: This email address is being protected from spambots. You need JavaScript enabled to view it.
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