KAREN NELSON MOORE, Circuit Judge. Under § 170(h) of the Internal Revenue Code, taxpayers who donate an easement in land to a conservation organization may be eligible to claim a charitable deduction on their Federal income tax returns. Crucially, the easement’s conservation purpose must be guaranteed to extend in perpetuity to qualify for the deduction. See 26 U.S.C. (I.R.C.) § 170(h)(5)(A). Unexpected developments, however, may make this impossible long after the donor has deeded the easement away. How, then, can an easement satisfy the perpetuity requirement?

Contemplating such scenarios, the Department of Treasury has promulgated a rule, 26 C.F.R. (Treas. Reg.) § 1.170A-14(g)(6). This regulation addresses situations in which unforeseen changes to the surrounding land make it “impossible or impractical” for an easement to fulfill its conservation purpose. Treas. Reg. § 1.170A-14(g)(6)(i). In these events, the conservation purpose may still be protected in perpetuity “if the restrictions are extinguished by judicial proceeding and all of the donee’s proceeds . . . from a subsequent sale or exchange of the property are used by the donee” to further the original conservation purpose. Id. Proceeds are calculated by a formula in § 1.170A-14(g)(6)(ii), a provision to which we refer as the “proceeds regulation.”

On this appeal from the United States Tax Court, the petitioners, Oakbrook Land Holdings, LLC (Oakbrook) and William Duane Horton, challenge the validity of the proceeds regulation. The petitioners contend that, in promulgating this rule, Treasury violated the notice-and-comment requirements of the Administrative Procedure Act (APA). The petitioners also argue that Treasury’s interpretation of § 170(h)—the statute that the rule implements—is unreasonable. Finally, the petitioners argue that the proceeds regulation is arbitrary or capricious. The full Tax Court considered these arguments and found them to be unpersuasive. See Oakbrook Land Holdings v. Comm’r, 154 T.C. 180, 181 (T.C. 2020). We agree with the Tax Court and AFFIRM.