It's bringing 350 new jobs to the area in the heart of California wine country.
"It's humungous, it has some really cool things you would not think Costco would carry but it adds flavor to what we already have in the area" Justin Altares, a Vallejo resident said.
VIDEO: Michelle Obama spotted at East Bay Costco promoting new drink brand
Michelle Obama spotted at East Bay Costco promoting new drink brand
Costco opened its first location in Napa Friday morning.
"Well there was people in line waiting overnight, I think a couple of days so it seems like the demand is right there," Bernie Narvaez, the Vice Mayor of Napa said.
Narvaez says this is bringing 350 new jobs to the city.
"Anything that creates jobs is good for the economy, good for our business community, you know it adds competition," he said.
Complete with high-end handbags, electronics, clothes and Costco's biggest wine selection in the U.S., according to the retailer.
"They better, that's what we're here for!" Cory Culp, a Costco shopper said. "We're wine country so they better have a good selection."
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Cory and Hannah Culp say, Friday's Grand Opening couldn't have come sooner.
It would normally take up to an hour to get to the closest Costco from their home in the upper Napa Valley.
"It's a lot more convenient because you either go to Fairfield or Santa Rosa so this is more convenient," Hannah Culp, a Costco shopper said.
And an opening day wouldn't be complete without a celebrity whiskey signing, by none other than UFC Octagon Announcer Bruce Buffer.
"I've got three different versions out today, 14-year reserve, my single barrel and my regular," Buffer said. "I'm just very happy to be meeting everybody, people are buying bottles like crazy, taking pictures, I think they're all having a good time! I'm even blown away too because I'm standing here, I see all these great buys around the store, I think I've already spent around $10,000 dollars in my head!"
The retired founder of Costco, Jim Sinegal will also be at the new location signing wine bottles from 11 a.m. to 1 p.m. on Friday.