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About Us

About Our Firm

O'Donnell & Dennis, CPA's, LLC is committed to your success. We make it our business to know your business well enough to improve your tax position, capital position, business structure and benefits packages, acquisition potential, and much more. We earn our fees by adding value to your company and to your asset base.

We have learned a great deal since we began in this business, and we are ready to apply this knowledge to enhance your company's growth and success. Together we can conquer all of the intricacies of doing business in today's fast-paced economy.

We are looking forward to working with you!

Our Mission

Our mission is to help clients maintain financial viability in the present, while taking a proactive approach to achieve future goals. This requires open communication to reach an understanding of our clients' needs through research and sound analysis. O'Donnell & Dennis, CPA's, LLC is dedicated to meeting these goals with high standards of excellence and professionalism. We have been a staple of the area's business community for years, and pride ourselves on the level of esteem we have earned.

Our dedication to hard work has earned the respect of the business and financial community in and around the area. We believe this to be a direct derivative of our talent and responsiveness to our client base. Whether you are a current or prospective client, rest assured that individuals and businesses who choose O'Donnell & Dennis, CPA's, LLC receive competent and timely advice.

Our Team

Sam D. Dennis, CPA (303) 776-5908 Ext 12

Sam D. Dennis, CPA, has for more than a quarter century served a wide spectrum of clients in the practice of public accounting. Sam's background of expertise includes in depth experience in tax consultation, preparation and planning for individuals, partnerships, corporations, estates and trusts.

Since completing his baccalaureate degree in accounting in 1989 and prior to joining the firm in January 2015, Sam owned and managed a corporate public accounting practice in Maryland for the past more than two decades. With a license to practice accounting, Sam has been active in the State Accountancy Societies in both Colorado and Maryland. He also has served such charitable interests as the internationally recognized Congressional Hunger Center, where he regularly consulted and guided the board of directors in strategic planning.

With a long family history in Colorado, Sam and his wife, Michelle, take pleasure in hiking, relishing and appreciating the overall scenic beauty of the majestic Colorado mountains.

Todd A. O'Donnell, CPA (303) 776-5908 Ext 15

Todd A. O’Donnell, CPA, has been in public practice since 1986. Todd has over 20 years of accounting and tax experience which includes working as a Sole Proprietor for over 15 years. He provides individual, business and fiduciary accounting and tax services as well and business consulting services.

Todd graduated from the University of Northern Colorado in 1986 with a Bachelor of Science degree. He is a member of the American Institute of Certified Public Accountants and the Colorado Society of Certified Public Accountants. Todd is an active member in the community, most recently as a member of the board of directors for the Tiny Tim Center.

Todd currently lives in Longmont with his wife Cathy and daughter Ryleigh. He has lived in the Longmont area since 1976 and graduated from Longmont High School in 1981.

Louise M. Slaughter, CPA (303) 776-5908 Ext 11

Louise M. Slaughter, CPA, joined the firm in January 2008. She brings over 30 years of accounting experience in multiple private industries. Louise provides accounting and tax preparation services for corporations, partnerships, limited liability companies and individuals.

Louise graduated Summa Cum Laude from Youngstown State University, Youngstown, Ohio in 2002 with a Bachelor of Science Degree in accounting.

Louise lives in Erie with her husband, Richard, and 2 dogs, Nieko & Harmony. She is a member of the Flatirons Kennel Club, and the Swedish Vallhund Club of America.

Kevin E. Mines, CPA (303) 776-5908 Ext 13

Kevin E. Mines, CPA, has worked at the firm since 2014. Kevin obtained his Colorado CPA license in 1986. He has decades of experience providing tax services for clients with complex situations and high net worth individuals, as well as preparation of Partnership, Corporation, Estate and Trust tax returns.

Kevin graduated from Brigham Young University with a Master of Accountancy degree. Upon graduation, he worked for Deloitte & Touche accounting firm in Colorado Springs for several years. Kevin was promptly promoted to Tax Manager position to lead in overseas location in Dhahran, Saudi Arabia. He went on to work at Saudi Arabian Oil Company (also known as Saudi Aramco). Kevin later owned and operated a tax business in Granby, Colorado for about a decade.

Kevin and his wife, Carren, live in Lafayette and have raised four ambitious sons: three are college graduates, and the youngest is in high school.

Sheri K. Martinez (303) 776-5908 Ext 10

Sheri K. Martinez joined the firm in January 2020, as Administrative Associate. She has extensive secretarial administration of 25 years under her belt. She has been a resident of Longmont city for over two decades.

Sheri and her husband, Ken, have three sons and eight grandchildren. They enjoy camping in the beautiful Rocky Mountains and spending time with their family.