Joint unified school districts or joint high school districts may be created lying in part in each of two or more counties in the same manner as joint common school districts may be created under this article, except as expressly provided in sections 15-450 and 15-451. Except as expressly provided in sections 15-429, 15-450, 15-451, 15-453 and 15-455 through 15-457, section 15-491, subsection B, and sections 15-975 and 15-997, each joint high school district or joint unified school district shall have all powers and duties, shall be operated and maintained and shall follow and be subject to procedures as may be provided by law for the operation of other school districts.
A.R.S. § 15-454