White Mountain Center v. County of Maricopa

The Arizona Medical Marijuana Act (AMMA) decriminalized certain medical uses of marijuana and immunized AMMA-compliant marijuana users from being penalized under state law. The AMMA also authorized the establishment of medical-marijuana dispensaries (MMDs) and empowered the Arizona Department of Health Services to establish a registration and tracking system for MMDs. White Mountain Health Center, Inc. (White Mountain) (plaintiff) applied to Maricopa County, Arizona (the county) (defendant) for zoning approval to establish an MMD pursuant to the AMMA. The county denied the application, reasoning that approving the application might subject Maricopa officials to prosecution under the federal Controlled Substances Act (CSA). White Mountain challenged the county’s decision in court and moved for summary judgment, requesting that the trial court order the county to issue the zoning authorization. The county also moved for summary judgment, arguing that federal law preempted the issuance of zoning authorization for the MMD because (1) it was impossible for county employees to comply with both the AMMA and the CSA, and (2) the AMMA created an obstacle to the federal government’s enforcement of the CSA. Both White Mountain and the county agreed that the CSA did not occupy the field of drug regulation, nor did it expressly preempt state law. The trial court found that neither impossibility preemption nor obstacle preemption applied and granted partial summary judgment to White Mountain. The county appealed.