A patch of vacant land near Interstate 10 and Sunset Road in northwest Tucson that Pima County hopes to sell to Costco for $15 million is sitting on top of cultural deposits more than 3,000 years old, including ancestral human remains, footprints and some of the earliest known irrigation agriculture in North America north of Mexico. Before any shovel breaks ground, the county now has to work through a process that starts with talking to the tribes whose ancestors may be buried there.
County Opens Formal Talks With Tribal Nations
Pima County is beginning government-to-government consultation with tribal nations over the roughly 56.66-acre parcel at the southwest corner of the I-10 and Sunset Road interchange, according to KVOA. The station reports the property contains extensive, deeply buried cultural deposits dating back more than 3,000 years, along with evidence of early Hohokam settlements layered atop that ancient irrigation history. As first reported by KJZZ, Pima County signed a nonbinding letter of intent last month to sell the land to Costco Wholesale Corporation.
The address at the center of the deal is 3601 W. Sunset Road, the same southwest interchange corner described in the county's filings. A third-party appraisal in June valued the land at a market value of $15 million, matching the proposed purchase price, according to KGUN9. That appraisal, notably, did not weigh in on what sits beneath the surface: archaeological resources were left out of the valuation because the compliance requirements, treatment needs and mitigation costs fell outside the appraiser's scope and expertise.
Due Diligence, Earnest Money and a Long Road to Approval
Under the terms described by KVOA, Costco would put down $150,000 in earnest money and has up to 150 days for feasibility contingencies and 180 days for approval contingencies, with the ability to extend both windows. The letter of intent calls for due diligence and negotiations on a possible sale, not a finished transaction, as KGUN9 notes. Next steps include granting Costco a right of entry for site due diligence, conducting internal county reviews, and commissioning an economic impact analysis.
Pima County's Cultural Resources and Historic Preservation Office is responsible for advising both the county and Costco on applicable cultural resources requirements, the station's report adds. Costco itself has stayed quiet, declining to comment on the potential location and citing a company policy against discussing future warehouses until two to three months before opening.
Arizona Law and the Weight of Precedent
Arizona law gives the county a clear obligation once old material turns up during work on public land. Under Arizona Revised Statutes § 41-844, anyone overseeing work who discovers archaeological, paleontological or historical material at least 50 years old must promptly report it to the director of the Arizona State Museum and, in consultation with that office, take all reasonable steps to secure and preserve it. Separately, under Arizona Revised Statutes § 39-125, information about the exact location of archaeological discoveries and sites eligible for the state historic register can be kept confidential, though the full scope of that exception is not spelled out in the statute itself.
Tucson-area history offers a cautionary tale for how badly these situations can stall a project. A planned condominium development near Continental Ranch was stalled by disputes over the protection and removal of ancient Hohokam burial sites and artifacts, according to Tucson.com. Town archaeology reports suggested that site could have been part of a Hohokam village populated between 550 and 900, and while the developer's own archaeologist found three burial sites during an initial survey, a two-day search funded by the town of Marana turned up 24.
Other recent Tucson-area cases underscore how fraught these negotiations can get once remains are confirmed. A Burial Discovery Agreement and coordination with the Tohono O'odham Nation were required for the Casita Village archaeological excavation, according to KOLD. And further south, a study released in September found that the Las Playas Intaglio, a sacred site damaged by bulldozers during border wall construction last spring, is more than 6,000 years old, per AZPM.
For now, the Sunset Road site remains vacant land awaiting due diligence, not a confirmed Costco warehouse. The company has not publicly committed to building there, and the county's consultation with tribal nations is only beginning, meaning the fate of the ground, and what lies beneath it, is still unresolved.
