The taxpayers, three pairs of landowners, created conservation easements on their lands, had the easements appraised and sold them to a land trust for a portion of their appraised value. They claimed state (CO) income tax credits on their 2004 returns which they applied against their income tax liability, carrying the balance of the credits forward. In late 2009, the defendant (CO Department of Revenue) disallowed the credits due to an alleged deficiency in the appraisals. The taxpayers claimed that the statute of limitations period had run before the defendant acted to disallow the credits. The trial court agreed and granted summary judgment to the taxpayers. On appeal, the defendant claimed that the statute of limitations began to run each time a donor (or transferee of the credits) applied the credits to their tax liability. The appellate court affirmed, noting that Colo. Rev. Stat. Sec. 39-21-107(2) specified that the defendant had to make assessment of tax within one year of the expiration of the statute of limitations of the time provided for assessing a deficiency in federal income tax. The federal statute of limitations is three years. Thus, the question was what event triggered the commencement of the four-year period. Based on legislative history, the appellate court determined that the legislature did not intend the limitations period to restart each time a conservation easement credit is used. Such a construction would, the court noted, yield the unacceptable result of allowing the defendant to potentially disallow a credit claimed 24 years earlier. Markus, et al. v. Brohl, No. 13 CA1656, 2014 Colo. App. LEXIS 1788 (Colo. Ct. App. Oct. 23, 2014).