A large data center campus could be coming to the outskirts of Phoenix, Arizona.

First reported by BizJournal, the Maricopa County Board of Supervisors last week approved a request to rezone a 638-acre site located at the northeast corner of 491st Avenue and Thomas Road, outside Tonopah to the west of Phoenix.

The rezoning, to IND-2 Zoning District, allows for industrial uses including data centers and accessory uses, electric substations, battery storage, and power generation facilities for on-site utilization or sale to a utility or other off-site users.

At full build-out, the site could be home to as many as nine 250,000 sq ft (23,225 sqm) data center buildings totaling 2.25 million square feet (209,030 sqm), according to a project narrative document.

Full details of the planned development haven't been shared.

The county planning commission unanimously recommended approval for the project at a meeting last month. County staff had recommended approval.

The site is owned by site is owned by Grandilla Arizona Inc. and Foot Creek Corporation.

The land is close to Capital Power’s Harquahala Generating Facility, a 1GW combined cycle gas-generation facility. Launched in 2004, the site is jointly owned alongside BlackRock after the two companies acquired the plant in 2024.