A.R.S. § 9-401: Acquisition of land by city; extent and notice of city jurisdiction

A. A city or town may purchase, lease or rent land, whether contiguous or noncontiguous, lying outside its corporate limits, for its purposes and uses, and any violation of an ordinance of the city or town occurring within the territorial limits of the land may be punished by the city or town having control thereof to the same extent and with like effect as if the violation occurred within the corporate limits.

B. At any point at which a public road enters land purchased, leased or rented as provided by subsection A, the city or town having control thereof shall erect and maintain a sign, not less than eighteen inches by three feet in size, containing a warning notice in bold letters that the area being entered is subject to the jurisdiction of the city or town.