The Oklahoma Bar Journal January 2026

a position to alter Thielenhaus. However, the Court of Civil Appeals has, at times, appeared to recognize the limitations of the separate property presumption and the inequitable results that can result from its application. In the case of Dancer v. Dancer , 50 the court found that the evidence necessary to support the wife’s in-marriage enhancement claim as required by Thielenhaus was not present in the record. Rather than denying the wife’s claim for fail ure to meet the burden of proof, the court remanded the matter for presentation of further evidence: [W]e reiterate dissolution of marriage proceedings are equi table in nature ... this Court will not proscribe Wife from claim ing an equitable portion of the marital home’s enhanced value. Instead, we remand the marital home issue to the trial court to ensure the enhanced value of the marital home is fairly and equitably divided. 51 In light of the equitable nature of dissolution of marriage pro ceedings, the court chose to permit additional evidence rather than bar the wife’s claim. However, a rule that creates situations in which equity requires trial and retrial in hopes of reaching an equitable result is not a practical solution. 52 Thielenhaus has governed the division of in-marriage enhance ment of separate assets for 30 years. As noted above, the allocation of burden of proof does not appear to be the result of careful judicial consideration, but rather the result of accident and inadvertence. The presumption that in-marriage CONCLUSION

trial court found “questionable.” 48 Following trial, the trial court found that the wife did not meet her burden under Thielenhaus and awarded the business, including the appreciation, to the husband as his separate property. While the Court of Civil Appeals ultimately reversed the decision on appeal, this case demonstrates that the burden of proof, as required in Thielenhaus, is deeply problematic when applied to actively managed assets like the small business at issue in Williams . There is no logical or principled reason that an asset managed as the full-time occupation of a spouse should be presumed by Oklahoma law to generate only passive growth in the absence of proof to the contrary. Rather, in-marriage enhancement of an actively managed asset should, consistent with Oklahoma’s marital property scheme, be presumed to be marital property. 49 With some very rare exceptions, businesses do not increase their value by 400% to 1,300% within six years as a result of passive appreciation or market forces. Parties who manage busi nesses as their primary occupation do not do so in hopes that market forces and circumstances beyond their control will generate passive growth. They do so because they believe their efforts will increase the value and profitability of the business. The presumption required by Thielenhaus entirely fails to reflect this reality. The Oklahoma Supreme Court has not addressed in-marriage enhancement to any significant extent since the Thielenhaus deci sion in 1995. Cases regarding in-marriage enhancement have been left to the Oklahoma Court of Civil Appeals, which is not in

enhancement of a separate asset is separate property is largely contrary to Oklahoma’s marital property scheme. Perhaps after 30 years, the Thielenhaus decision is due for reconsideration.

ABOUT THE AUTHOR

Ryan J. Reaves is a partner at Mullins Mullins Sexton & Reaves PC. His practice focuses almost exclusively on family law matters

with an emphasis in appellate representation. Since graduating from the OU College of Law in 2008, Mr. Reaves has represented clients in more than 70 appellate and original jurisdiction matters, resulting in seven published decisions. Mr. Reaves is a regular presenter at the OBA Family Law Section Annual Meeting. 1. 1995 OK 5, 890 P.2d 925. Research suggests that Thielenhaus has been cited in at least 61 published decisions in Oklahoma; by courts in other jurisdictions, including Virginia, West Virginia and Nebraska; and by bankruptcy courts in both Oklahoma and Texas. 2. Thielenhaus , ¶9, 931 (emphasis added). The “three critical value-assessment elements” were derived from May v. May , 1979 OK 82, 596 P.2d 536. https://bit.ly/44bZGFp. 8. Matter of Burgess’ Estate , 1982 OK CIV APP 22, 646 P.2d 623, favoring prenuptial agreements being a possible exception. 9. Colclasure v. Colclasure , 2012 OK 97, 295 P.3d 1123; Sien v. Sien , 1994 OK CIV APP 159, 889 P.2d 1268. 10. Manhart v. Manhart , 1986 OK 12, 725 P.2d 1234. 11. Smith v. Villareal , 2012 OK 114, 298 P.3d 533; Larman v. Larman , 1999 OK 83, 991 P.2d 536. 12. Gray v. Gray , 1996 OK 84, 922 P.2d 615. 13. Catron v. First National Bank & Trust Co. of Tulsa , 1967 OK 107, 434 P.2d 263; Gillett v. McKinney , 2019 OK CIV APP 24, 440 P.3d 69. 14. 1982 OK 127, 656 P.2d 250. 15. 1994 OK 30, 872 P.2d 395. 16. Thielenhaus , ¶9, 930 (“The burden is upon the non-owning spouse to show that the enhancement is the result of either spouse’s endeavors.”). ENDNOTES 3. 1982 OK 127, 656 P.2d 250. 4. 1962 OK 146, 372 P.2d 844. 5. 1979 OK 82, 596 P.2d 536. 6. Thielenhaus , ¶10, 931. 7. Id .

Statements or opinions expressed in the Oklahoma Bar Journal are those of the authors and do not necessarily reflect those of the Oklahoma Bar Association, its officers, Board of Governors, Board of Editors or staff.

JANUARY 2026 | 21

THE OKLAHOMA BAR JOURNAL