On June 19, 2017, the Colorado Supreme Court ruled against the petition of Kinder Morgan CO2 Co., LP — the operator of oil and gas leaseholds — disputing the Montezuma County Assessor’s 2009 corrective tax assessment on leaseholds for the prior tax year which resulted in a retroactive assessment of over $2 million in property taxes. Kinder Morgan CO2 Co., L.P. v. Montezuma County Board of Commissioners; Colorado Board of Assessment Appeals; and Colorado Property Tax Administrator. The Board of Assessment Appeals upheld the retroactive assessment finding that Kinder Morgan had underreported the selling price of its production by over-deducting its costs.

Oil and gas leaseholds and lands are valued under Colorado statutes, Article 7 of Title 39, pursuant to which a lessee must submit an annual statement (reporting the volume and price of product sold at the wellhead), following which the county assessor determines property value and tax liability. See § 39-7-101 -103(2). Because the sale of unprocessed oil or gas rarely occurs at the wellhead, an operator usually estimates the wellhead selling price, deducting costs for, e.g. gathering, processing, and transporting the extracted material – called the “netback” method of calculating the wellhead price. See § 39-7-101(1)(d) (“The net taxable revenues shall be equal to the gross lease revenues, minus deductions for gathering, transportation, manufacturing, and processing costs borne by the taxpayer pursuant to guidelines established by the [Property Tax Administrator].”). The resulting price for purposes of § 39-7-101(1)(d) is an estimate. An “operator’s netback calculation depends on whether the operator contracts with a related or an unrelated party to perform these gathering, processing, and transportation services. If the operator enters into a bona fide, arm’s-length transaction with an unrelated party to perform these services, then the operator may deduct the full amount paid for these services from its final, downstream sales price in its netback calculation (the ‘unrelated-parties netback method’). See 3 Div. of Prop. Taxation, Colo. Dep’t of Local Affairs, Assessor’s Reference Library: Real Property Valuation Manual (ARL) 6.35–6.36 (Rev. Jan. 2017).” Accordingly, if, as here, “the operator instead enters into a transaction with a related party . . . then it may deduct only a portion of the amount paid for these services (the ‘related-parties netback method’). 3 ARL 6.39–6.41.” (Emphasis added.)

In this case, Kinder Morgan contracted with Cortez Pipeline to compress and transport production. Cortez Pipeline is operated and 50% owned by Kinder Morgan. The Court concluded that Kinder Morgan had incorrectly used the unrelated-parties netback method in calculating its cost-deduction netback calculation. Further, the Court rejected Kinder Morgan’s argument that the property statutes do not authorize retroactive assessments when an operator has underreported the selling price of oil or gas, finding that § 39-5-125(1), C.R.S., and the Legislature’s amended statutory scheme governing property taxation of oil and gas leaseholds and lands “authorizes the retroactive assessment of taxes when an operator has underreported the selling price of oil or gas.”