Across State Route 24 from Cadence at Gateway, a long-vacant stretch of the former General Motors proving grounds is being positioned for one of the largest development projects proposed in the East Valley.
Legacy Park is a planned mixed-use district at the northeast corner of Ellsworth and Williams Field roads in southeast Mesa. Current plans combine upscale retail and restaurants with apartments, offices, a resort hotel, a large public park and a lake.
As of our October 22 review, we have not verified a Legacy Park groundbreaking announcement or a firm opening date.
Latest update — October 22, 2026: The published October 15 deadline for Legacy Park’s lake-and-park design qualifications has passed. We have not verified a designer selection or construction award. Mesa’s October retail review points back to September’s approvals; it does not announce a new groundbreaking or tenant opening.
Agreement update — September 22, 2026: The City of Mesa’s September 15 announcement confirms unanimous approval of the Legacy Park and Gateway Crossing development agreement on September 14. Our agreement approval report explains the funding terms, minimum commitments and deadlines. We have also added our Gateway Crossing and planned Sam’s Club report below; a store opening date has not been verified.
Image update — September 13, 2026: The AI-generated concepts in this story interpret published Legacy Park plans. The hero uses our drone photography as its starting point; buildings, landscaping and amenities are illustrative. These are independent concepts, not official developer renderings. The August 2026 community plan makes the lake optional and limits it to 10 acres if included.
What is planned at Legacy Park?
Vestar and Pacific Proving are presenting Legacy Park as a regional destination rather than a conventional neighborhood shopping center.
At full buildout, the developers’ public materials describe:
Approximately 300,000 square feet of upscale retail and restaurants
About 2,500 multifamily residences
A 600-room resort hotel and conference center
Approximately 3.4 million square feet of office and corporate-campus space
A public park of more than 20 acres organized around a large lake
Walking paths, plazas and connected green space
The retail and restaurant component has been compared with Scottsdale Quarter, where shops, restaurants, offices and residences are combined in a walkable outdoor district.
No specific retail or restaurant lineup has been publicly released. Vestar has said it is pursuing chef-driven restaurants and retailers that would be new to the East Valley, but those descriptions should not be treated as tenant announcements.
What could be included in the first phase?
The current Legacy Park leasing brochure places the project’s major lifestyle components in the initial phase.
Those plans show approximately 700 rental residences, the retail district, office space, the lake and park, a fitness center and the resort. The brochure specifically identifies a 600-room JW Marriott and a roughly 100,000-square-foot Life Time Fitness.
Those names appear in current project marketing materials, but neither business has published a project-specific opening date. Until additional announcements are made by the companies involved, they are best described as planned components rather than open or under-construction locations.
Project details may also evolve during zoning, design, leasing and construction. Even current materials contain small differences in some square-footage totals, another reason to treat the numbers as plans rather than fixed promises.
Where would Legacy Park be located?
The site sits at the northeast corner of Ellsworth and Williams Field roads, immediately south of State Route 24 and beside Arizona Athletic Grounds.
For Cadence residents, Legacy Park is close—but it is not part of Cadence. The existing neighborhood sits across SR 24 from much of the proposed development area.
The project is also near Phoenix-Mesa Gateway Airport, ASU Polytechnic and the growing employment corridor extending through southeast Mesa, Gilbert and Queen Creek.
Its freeway exposure is a major part of the plan. Developer materials emphasize access from two SR 24 interchanges and a regional trade area reaching Mesa, Gilbert, Queen Creek and San Tan Valley.
This is not the former Legacy Park sports complex
The name is likely to create some confusion.
Arizona Athletic Grounds, the large sports complex next to the proposed development, previously operated under the names Legacy Park and Bell Bank Park.
The new Legacy Park discussed here is a separate mixed-use development proposed on adjacent land. It would contain retail, housing, offices, hospitality and public open space rather than sports fields and athletic facilities.
When could Legacy Park open?
The older developer announcement targeted 2027 groundbreaking. Newer reporting from KTAR, citing the Phoenix Business Journal, points to construction in early 2028 and a first-phase opening in October 2029. These remain reported expectations.
The posted development agreement sets separate reimbursement-eligibility deadlines: commencement by December 31, 2029; completion and required conveyance by December 31, 2034; and the luxury hotel open by December 31, 2035, subject to applicable extensions. These contractual deadlines are not announced opening dates. Read the agreement and schedule explainer for sources and context.
Development may proceed in phases, and subsequent buildout could extend beyond the initial openings.
Legacy Park approval timeline and latest coverage
August 26, 2026: Mesa’s Planning and Zoning agenda listed case ZON25-00891, a request to rezone approximately 196.3 acres from Light Industrial to Planned Community District.
August 27, 2026: The council adopted a notice of intent for a proposed tax-incentive agreement, according to Mesa Independent. The reported vote was 6–1; the city’s online minutes remain draft.
August 31, 2026: Mesa Independent reported introduction of the related annexation and rezoning ordinances. Introduction is distinct from final adoption.
September 14, 2026: Mesa approved the development agreement unanimously, as confirmed in the city’s September 15 announcement. KTAR also reported related land-use and district actions. Read our agreement approval and funding explainer.
Our August council actions explained includes links to the city report, resolution, zoning case and the reporting behind the vote tally. This guide will collect future substantive updates here.
September 17, 2026: Our Gateway Crossing report examines leasing materials identifying Sam’s Club as the planned anchor of the related shopping center southwest of SR 24 and Williams Field Road. Gateway Crossing and Legacy Park are distinct projects; a timeline for Legacy Park does not establish a Sam’s Club opening date.
Lake and park design procurement
A notice dated September 17 and published in the Arizona Business Gazette on September 17 and 24 seeks qualified firms for Legacy Park’s lake and park design, identified as Offsite Package #4. Vestar Pacific Master Plan, LLC is the developer; Foursite Consulting administers the request.
The notice listed an online pre-submittal conference for October 1 at 1 p.m. and a qualifications deadline of October 15 at 2 p.m., both Phoenix time. Those advertised dates have passed; the notice alone does not show whether the process was extended or a firm selected. It does not announce a designer selection, construction award, groundbreaking or opening date. The full RFQ package is available by request through the administrator identified in the notice.
What Cadence residents should watch
For nearby residents, Legacy Park could eventually change the range of restaurants, shopping, recreation and hospitality available within a short drive.
It could also affect traffic and construction patterns around Ellsworth Road, Williams Field Road and the SR 24 interchanges. Road capacity, access points and the timing of surrounding improvements will become more important as the project advances.
The biggest milestones will be:
Posted final action records, permits and implementation of agreement conditions
Confirmation of the hotel and fitness components
The first named restaurants and retailers
A construction contract and formal groundbreaking
Opening dates for the initial phase
Until those steps occur, renderings should be understood as a vision for the site—not a picture of work already underway.
What remains unknown
Several of the questions nearby residents are most likely to ask still do not have firm public answers.
Our October 22 review did not verify a newly announced shop or restaurant lineup, a firm grand-opening date or a groundbreaking announcement. This was a records review, not a new site inspection. The newer reported construction outlook remains an expectation, not a guarantee.
East Valley Explorer will update this story as permits, design awards, tenant announcements and construction milestones become available.
