Late last month, interim mayor Tim Burgess said the city would be backing a county effort respond to Amazon’s call for a second headquarters location. Last week, we learned what form Seattle’s bid to take on all of Amazon’s expansion will take: King and Snohomish Counties are working together to make a collective bid.

King County executive Dow Constantine and Snohomish County executive Dave Somers announced Thursday that they’d be coordinating a response to Amazon’s call for a city where they can build a second headquarters, frequently referred to as HQ2.

Cities participating in the bid include Marysville, Bellevue, Bothell, Everett, Renton, Lynnwood, and Tukwila. The Tulalip tribes have also signed on. Seattle is not officially on the list, although city staff are helping to put together background information.

In their statement, the executives said that a regional proposal will be more competitive.

Several potential sites—the “shovel-ready” site Amazon asked that proposals include—will be part of the proposal in both participating cities and on tribal lands. Emails obtained by the Puget Sound Business Journal (PSBJ) name a few sites that could be candidates, including Everett’s Riverpoint and Public Works Service Center and Lynnwood City Center.

Individual municipalities can opt to include their own tax or talent incentives, as Amazon has shown a preference for.

They plan to submit a final proposal to Amazon on October 17, and say they’ll have more details at that time.

Meanwhile, Pierce County is submitting their own proposal. Speaking with PSBJ earlier this week, Tacoma mayor Marilyn Strickland said that they were approached by the coalition, but ultimately declined: “Amazon should remain in the central Puget Sound region... but, at the end of the day, our proposal will be stronger if we submit it as Tacoma and the south Sound.”

Staying in the same metropolitan area might not help the tech giant attract much talent they couldn’t get in Seattle—but it looks like we’re getting at least two bids out of the area regardless.

This article has been updated to clarify the City of Seattle’s involvement.