Corey T. Denevan - a Sioux Falls, United States Trust, Estate and Guardianship Lawyer

Sioux Falls Trust, Estate and Guardianship Lawyer

Updated: 03/02/2026

Areas of Practice

Trust, Estate and Guardianship
Business Planning and Succession
Real Estate Transactions
Creditor Rights
Commercial Litigation
Conservatorships
Will Contests
Probate Administration
Inter-family Disputes
Contractual Matters
Durable Powers of Attorney
Estate, Gift and Income Tax Issues
Elder Abuse and Neglect
Fiduciary Duties
Partnership and Corporate Governance

Attorney Information

Overview

Corey was born and raised in Sioux Falls, South Dakota. However, he began his professional career on the West Coast in Seattle, Washington. He was an assistant vice president and trust officer with one of the nation’s largest financial institutions. Corey transitioned to the practice of law at Hertog & Coster, PLLC, where he focused on estate planning, probate administration, and the representation of non-professional fiduciaries and professional fiduciaries, such as banks, trust companies, and guardianship agencies.

Corey joined Aiken, St. Louis & Siljeg, P.S. as a shareholder, where he continued to manage complex trust, estate, and guardianship matters, but also expanded his practice into business planning and succession, real estate transactions, creditor rights, and commercial litigation. Corey also served as a court-appointed trustee and personal representative in complex and contentious cases.

Corey was a longstanding member of the Washington State Bar Association’s Real Property & Probate Section and Guardianship and Elder Law Section, as well as the King County Bar Association’s Real Property & Probate Section and Elder Law Section. Corey served two terms on the executive committee of the King County Bar Association’s Elder Law Section.

In 2005, Corey was nominated and served as the chair of a committee with judges and court commissioners to draft forms to be used by guardians and trustees to report on their fiduciary activities. In 2012, Corey was nominated and served as co-chair of the Washington State Bar Association’s task force to revise the Uniform Durable Power of Attorney Act to reduce the financial exploitation of vulnerable and elderly persons.

After twelve years on the West Coast, Corey and his wife returned to Sioux Falls to be closer to their families. Upon returning to Sioux Falls, Corey served as an adjunct professor at a local university, teaching employment law.

Corey joined Boyce Law Firm, LLP in 2013, and as a partner at the firm, he focused on trust litigation representing fiduciaries, beneficiaries, and entities owned by trusts both nationally and internationally. He also continues a small estate planning practice and represents family members in guardianship and conservator proceedings. Corey is a frequent presenter at continuing legal education seminars for lawyers. Corey has been a presenter at over 50 seminars in Washington, California, South Dakota, Iowa, Ohio, Florida, Toronto, and London. Corey has also been involved in legislative activities.

In 2020, Corey chased a long-held ambition to start his own business and opened Denevan Law Prof. LLC. In late 2022 and early 2023, Shannon and Meghann joined forces with Corey and Denevan Falon Joyce was born. Corey continues to focus on trust and estate litigation, administration, and planning, as well as guardianships, conservatorships, and business litigation.

During his time at the University of Missouri – Columbia School of Law, each course Corey took had a component aimed at developing skills in negotiation, mediation, arbitration, and problem solving, which sparked his passion for alternative dispute resolution. A majority of the cases that he has been involved in over the last seventeen years involved mandatory mediation, and a few cases required arbitration. Corey is adept at and fond of the process of mediation and arbitration.

The skills necessary to successfully mediate a case do not always require expertise in a particular field of law. Mediation is more about developing an understanding of the interests of the parties and finding opportunities for resolution.

While Corey has litigated numerous cases through trial and appeal, his most gratifying work has been in the area of alternative dispute resolution. Serving as a mediator or representing a client in mediation and creating a forum for the parties to control and craft their own resolution is very gratifying. Corey has witnessed how the mediation process can provide a catharsis for clients, resulting in a better outcome that is not necessarily achievable through traditional litigation. He has also found that arbitration can provide a more expedient, efficient, cost cost-effective means of resolving a dispute in private.

Awards and Honors

Honors

AV Preeminent®: The highest peer rating standard, Martindale-Hubbell, 2023
Marquis Who's Who, Honored Listee, 2023

Education

Legal Education
- University of Missouri School of Law (Columbia), Columbia, Missouri, 2000
  J.D.
  Honors: Opal A. Carlson Academic Scholarship
  Honors: CALI Legal Excellence for the Future Award – Secured Transactions
  Honors: Accommodation for Excellence in Agricultural Law
Non Legal Education
- Augustana University, Sioux Falls, South Dakota, 1996
  B.A., Biology
  Honors: Academic Scholarship Recipient
  Honors: Athletic Scholarship Recipient Football, NCAA Div. II

Current Employment Position(s)

```
Lawyer & CEO
```

Classes and Seminars

2023 IFG Toronto Cryptocurrency Update United States Perspective
2021 IFG London Trusts and Fraudulent Transfer Laws
2021 Ohio State Bar Association Asset Protection Cleopatra Cameron Case
2018 South Dakota Bar Association The Law of Inherited Stock
2017 NBI Trusts From A to Z “Ethical Considerations for Lawyers in Trust Matters”
2017 NBI Trusts From A to Z “Special Needs Trusts”
2016 NBI Estate Administration From Start to Finish: “Handling Estate Administration Tax Issues”
2016 NBI Estate Administration From Start to Finish: “Distribution and Closing of the Estate”
2015 NBI Trusts 101: “Estate Planning for the Disabled Client”
2015 NBI Trusts 101: “Ethical Considerations for Lawyers”
2012 Washington State Bar Association: Legislative Committee “Presentation of Revisions to Uniform Durable Power of Attorney Act”
2012 Washington State Bar Association: Paralegal Studies Seminar “New Changes to Washington Trust Act”
2012 Washington State Bar Association: RPPT Mid-Year Meeting “Revising the Uniform Durable Power of Attorney Act: Balancing Individual Autonomy and Protection from Financial Abuse”
2011 Title 11 Guardianship Guardian ad Litem Training “Less Restrictive Alternatives to Guardianship”
2011 King County Bar Association: Advanced Issues in Fiduciary Law: “Current Developments in Fiduciary Law”
2011 NBI Probate and Estate Administration: “Ethical Challenges in Estate Administration”
2011 Washington State Bar Association: Avoiding Elder Law Malpractice “Client Representation and Fee Agreements”
2011 Washington State Bar Association: “New Changes to Washington Trust Act”
2010 King County Bar Association: Advanced Guardianship Issues “Payment of DSHS/DDD Guardian and Attorneys Fees” Co-presented with Washington Attorney General’s Office
2009 National Business Institute: Sophisticated Probate Strategies “Procedural Updates” and “Preventing and Litigating Probate Disputes”
2009 Washington Association of Professional Guardians: “Payment of Guardian’s Fees and Costs from DSHS”
2008 King County Bar Association: Guardianship and Elder Law Section: “Bankruptcy and Guardianships: What You Need to Know”
2008 National Business Institute: Oddities and Challenges in Probate Law: “Probate Litigation” and “Solutions to Special Issues”
2006, 2007 & 2008 Title 11 Guardianship Guardian ad Litem Training: “Less Restrictive Alternatives to Guardianship”
2007 Washington State Professional Guardian Certification Training: “Guardian of the Estate Issues”
2007 Half Moon LLC, Continuing Education: Washington Estate Planning and Probate Practice for Paralegals: “Assisting in the Administration of the Probate Process”
2006 NBI The Probate Process from Start to Finish: “Litigating the Case in Probate Court” 2005
2005 Washington State Professional Guardian Certification Training: “Prudent Investor Rule”
2004 Washington State Bar Association Establishing, Managing and Terminating the Special Needs Trust: “Termination of Special Needs Trusts”
2003 National Business Institute: “Drafting and Managing Special Needs Trusts”
2003 King County Bar Association Advanced Minor Settlements Guardian ad Litem Program: “Presentation on Special Needs Trusts”
2002 Wells Fargo Bank Seminars on Estate Planning and Special Needs Trusts
2002 Orange County Bar Association (California) Trustee Panel Discussion: “Management of Special Needs Trusts”.
2002 Presentation to Iowa Trial Lawyers: “Drafting and Managing Special Needs Trusts."

Bar Admissions

Washington, 2002
U.S. District Court Western District of Washington
U.S. Court of Appeals 2nd Circuit
South Dakota

Other Affiliations

South Dakota Bar Association
Washington Bar Association
Second Circuit Bar Association
King County Bar Association
International Fraud Group
American Bar Association
Wealth Counsel

Be the first to write a review!

There are currently no reviews for Corey T. Denevan. Be the first to share your experience.

Write a Review

Contact

Sioux Falls, SD

122 South Phillips Ave.
Suite 250
Sioux Falls, SD 57104

Directions

Phone: 605-800-8897

Email: Send a message

Websites:

Hours: 8AM - 5PM

Credit Cards Accepted
Free Consultations

Disclaimer

Your Profile? Update Now

When viewing a listing, consider the state advertising restrictions to which lawyers and law firms must adhere, as well as our FindLaw.com Legal Directory disclaimer. Some lawyers publish comparative information regarding the services that they provide which may be subject to specific comparative communications restrictions.

How do I choose a lawyer?

Consider the following:

Comfort Level – Are you comfortable telling the lawyer personal information? Does the lawyer seem interested in solving your problem?
Credentials – How long has the lawyer been in practice? Has the lawyer worked on other cases similar to yours?
Cost – How are the lawyer's fees structured — hourly or flat fee? Can the lawyer estimate the cost of your case?
City – Is the lawyer's office conveniently located?

Not sure what questions to ask a lawyer?

Here are a few to get you started:

How long have you been in practice?
How many cases like mine have you handled?
How often do you settle cases out of court?
What are your fees and costs?
What are the next steps?

Want to check lawyer discipline?

It is always a good idea to research your lawyer prior to hiring. Every state has a disciplinary organization that monitors attorneys, their licenses, and consumer complaints. By researching lawyer discipline you can:

Ensure the attorney is currently licensed to practice in your state
Gain an understanding of his or her historical disciplinary record, if any.
Determine the seriousness of complaints/issues which could range from late bar fees to more serious issues requiring disciplinary action.

Corey T. Denevan - Sioux Falls, SD