Closed-Bid Purchase Price Is Not a Required “Starting Point” for Cost-Approach Property Tax Valuation; Assessors May Rely on Credible Non-Manual Trend/Depreciation Sources

Case: Contango Resources, Llc v. Fremont County, Wyoming, 2025 WY 29 (Wyo. Mar. 17, 2025)
Court: Supreme Court of Wyoming
Subject: Ad valorem taxation; personal property valuation; cost approach; role of acquisition price; trending/depreciation sources; substantial evidence review

1. Introduction

Contango Resources, LLC purchased oil and gas production and processing assets from ConocoPhillips under a Purchase and Sale Agreement (PSA) for $67 million, covering property in both Fremont and Sweetwater Counties. For the 2022 tax year, the Fremont County Assessor valued only the Fremont County taxable property (not the oil and gas reserves) using the cost approach. Contango challenged the assessments before the Fremont County Board of Equalization, arguing primarily that (i) the PSA purchase price (and its “Allocated Value Schedule”) should have been used as the valuation “starting point,” and (ii) the Assessor and her retained appraiser used improper trending and depreciation factors (including sources outside the Department of Revenue’s Property Manual).

The County Board upheld the valuations; the State Board of Equalization and district court affirmed; and the Wyoming Supreme Court likewise affirmed—clarifying the discretionary role of acquisition price in cost-approach valuation, especially where the transaction was a closed bidding process and the taxpayer’s own itemized renditions conflicted with the purchase price.

2. Summary of the Opinion

The Court held that substantial evidence supported the County Board’s decision upholding the Assessor’s limited reliance on the PSA price. The Court rejected the claim that Wyoming law or Thunder Basin Coal Co. v. Campbell Cnty. requires an assessor to use acquisition price as the “starting point” under the cost approach. It further held that the Assessor (and her consultant) could use credible trending and depreciation data outside the Department of Revenue’s Property Manual, consistent with the Department’s rules and prior case law.

Key outcomes:

  • Acquisition price is permissive, not mandatory, as a starting point under the cost approach; assessors may choose historical cost where justified.
  • Closed-bid transactions may be disregarded as indicators of fair market value, particularly when the record lacks market-exposure detail.
  • Taxpayer renditions matter: the Assessor may rely on the taxpayer’s sworn, itemized renditions; the taxpayer bears the burden to supply valuation-relevant information.
  • Trending/depreciation sources: appraisers may use any credible source (not only the Property Manual), and a higher resulting value alone does not establish legal error.

3. Analysis

3.1. Precedents Cited

Standards of review and administrative posture

  • State v. Uinta Cnty. Assessor and Teton Cnty. Assessor v. Aspen S, LLC: The Court reiterated that its review focuses on the County Board’s decision (not the State Board’s or district court’s), applying Wyo. Stat. Ann. § 16-3-114(c) and asking whether the decision was lawful and supported by substantial evidence.
  • Gray v. Converse Cnty. Assessor and Bd. of Trustees of Lincoln Cnty. Sch. Dist. No. Two v. Earling: Cited for the “rational premise” formulation of substantial evidence—whether the record supports a reasonable basis for the agency’s fact findings.
  • Solvay Chemicals, Inc. v. Wyo. Dep't of Revenue: Cited for de novo review of agency legal conclusions.

Uniformity and rational appraisal methods

  • Thunder Basin Coal Co. v. Campbell Cnty. and Holly Sugar Corp. v. State Bd. of Equalization: Used to ground the constitutional requirement (Wyo. Const. art. 15, § 11) that assessors employ rational, equally applied appraisal methods producing essential fairness.

Presumption of correctness and burden shifting

  • Mountain Vista Ret. Residence v. Fremont Cnty. Assessor: Supplies the “strong presumption” in favor of the assessor’s valuation.
  • Helmut J. Mueller Ltd. P'ship v. Treanor: Explains shifting burdens: the taxpayer must first present credible evidence to overcome the presumption; if met, the assessor must defend; but the taxpayer retains ultimate burden of persuasion.

Purchase price / market exposure / closed bids

  • Thunder Basin Coal Co. v. Campbell Cnty.: Central to Contango’s argument. The Court distinguished it: Thunder Basin held acquisition cost was a permissible starting point supported by the record there; it did not impose a rule requiring acquisition price in all cost-approach cases.
  • Gray v. Wyo. State Bd. of Equalization (quoting Union Pac. R.R. v. Wyo. State Bd. of Equalization): Crucial to rejecting the PSA price as determinative because Contango’s transaction arose from a closed bidding process. These cases recognize that non-open-market processes can fail to establish “fair value” for assessment purposes, allowing assessors to disregard the sale price where circumstances justify.

Taxpayer’s burden to provide information; disagreement with valuation

  • Wyo. Dep't of Revenue v. Quest Corp.: Reinforces that the taxpayer bears the burden of supplying information necessary to value property.
  • Britt v. Fremont Cnty. Assessor (quoting BP Am. Prod. Co. v. Dept. of Revenue): Establishes the appellate role: courts do not pick the “best” appraisal method, but assess whether substantial evidence supports the chosen method.
  • Gray v. Converse Cnty. Assessor (also referencing Britt): Supports the rule that a mere difference of opinion as to value does not overcome the presumption favoring the assessor.

Issue preservation and briefing discipline

  • Pettengill v. Castellow (quoting Statzer v. Statzer): Used to decline review of issues not supported by cogent argument and authority (here, Contango did not brief trending/depreciation for the “less complex” property on appeal).
  • Sorenson v. Halling: Supports the Court’s refusal to consider new arguments on appeal (Contango’s “appraiser” definitional argument).
  • Keefe v. State: Cited for declining to consider inadequately supported arguments lacking legal analysis.

3.2. Legal Reasoning

(A) The PSA purchase price was not required as a “starting point”

The Court’s reasoning turned on the structure of the cost approach and the Department’s own guidance. The Property Manual recognizes multiple potential “starting point” costs (including “historical cost” and “original cost”) and warns assessors to distinguish “price” from “value,” because transaction prices can be influenced by financing terms, motivations, information asymmetries, and other non-market factors.

Against that backdrop, the Court rejected Contango’s claim that acquisition price must be the starting point whenever a purchase appears arm’s-length. Instead:

  • Transaction type mattered: the PSA arose from a closed bidding process, which Wyoming precedent treats as potentially non-indicative of “open market” value.
  • Information gaps mattered: Contango could not substantively explain how the PSA’s “Allocated Value Schedule” was derived, and the schedule did not assign values to specific items or differentiate between counties or reserves in a way that supported item-level assessment of Fremont County taxable property.
  • Taxpayer’s own sworn renditions conflicted: Contango submitted unchanged, sworn, itemized renditions listing historical cost, age, and condition; those renditions reflected a total value higher than the PSA price. The Court treated this conflict as justifying the Assessor’s request for more information and her decision not to anchor valuation to the PSA when Contango did not provide the needed allocation support.

(B) No arbitrariness from different uses of the PSA across the two dockets

Contango argued the Assessor acted arbitrarily because her consultant (valuing the “more complex” plant and gathering system) considered the purchase price as one data point for economic obsolescence, while the Assessor did not use the purchase price for the “less complex” assets.

The Court found no inconsistency because the purchase price was not used by anyone as the valuation “starting point.” The consultant’s limited use was confined to an obsolescence analysis tied to the plant’s economic yield—conceptually distinct from assigning starting-point costs to thousands of individual assets. In short, using the PSA price as a context clue for economic conditions did not compel using it as the foundational cost input for itemized valuation.

(C) Trending and depreciation factors may come from credible sources outside the Property Manual

The Court read the Department’s rules to expressly allow appraisers to use “any credible source” for costs and to permit depreciation rates “developed by the appraiser.” The Property Manual itself is described as a guide, not a substitute for appraisal knowledge and judgment. On that basis, the Court concluded it was lawful for TY Pickett to use trending and depreciation/obsolescence inputs developed from multiple credible sources (including industry data, Marshall & Swift, and studies), even if those differ from Property Manual tables.

The Court also emphasized what Contango did not show: it did not argue the sources were not credible; it argued only that using them raised value compared to the Manual tables. Under the presumption favoring the assessor, that is insufficient.

3.3. Impact

  • Reinforces assessor discretion under the cost approach: A recent purchase price—especially from a closed-bid process—does not automatically control assessments, and county assessors are not legally compelled to treat it as the starting point.
  • Elevates the practical importance of taxpayer renditions: Taxpayers who submit sworn, itemized cost schedules and later argue for a lower, deal-based value face an uphill battle unless they provide transparent allocations, supporting documentation, or independent appraisal evidence bridging the purchase price to the assessable property.
  • Signals litigation focus for future appeals: Challenges to trending/depreciation inputs will likely require direct attacks on credibility/validity (methodological flaws, lack of acceptance, misapplication), not simply demonstrations that alternative tables would reduce value.
  • Confirms non-exclusivity of Department guidance: The Property Manual is a guide; deviation is permissible where grounded in credible appraisal practice and consistent with rules—supporting broader use of specialized appraisal expertise for complex industrial assets.

4. Complex Concepts Simplified

  • Fair market value: The price a well-informed buyer and seller would agree to in cash-equivalent terms, without compulsion, after reasonable exposure to the open market.
  • Market price vs. market value: “Price” is what was paid in a particular deal; “value” is what the property would typically command under fair-market assumptions. A deal price can reflect special motivations, limited exposure, or financing terms that don’t represent “value.”
  • Cost approach: Values property by estimating today’s cost to replace it (“replacement cost new”) and subtracting depreciation/obsolescence to reflect age, wear, functional limits, and external economic forces.
  • Trending factor: An index-based adjustment that converts an older (historical) cost into today’s dollars (accounting for changes in construction/equipment costs over time).
  • Depreciation: Reduction from replacement cost new to reflect loss in value from age/condition (physical), design/utility issues (functional), or outside-market forces (economic obsolescence).
  • Economic obsolescence: A value loss caused by external conditions—e.g., market downturns, regulatory burdens, or reduced demand—that make the property less profitable or desirable.
  • Presumption in favor of the assessor: The assessor’s valuation is presumed correct; the taxpayer must produce credible evidence that the valuation method or application was legally or factually wrong.
  • Substantial evidence: Not “the best evidence,” but enough relevant evidence that a reasonable person could accept it as supporting the agency’s decision.

5. Conclusion

Contango Resources, Llc v. Fremont County, Wyoming confirms that Wyoming’s cost-approach valuation regime does not compel county assessors to use acquisition price as the valuation starting point—particularly when the purchase occurred through a closed bid process, the transaction allocations are opaque, and the taxpayer’s sworn renditions provide an alternative (and higher) historical-cost foundation. The decision also underscores that assessors and their consultants may depart from Property Manual trending and depreciation tables when relying on “credible” sources consistent with Department rules. For taxpayers, the case is a cautionary precedent: without transparent allocation support and credible valuation evidence, “we paid less” and “the Manual would be lower” will rarely overcome the presumption favoring the assessor’s appraisal.