Do they sell whiskey at this Costco ?

There is a liquor store, but it's not Costco's, they're an independent store that is adjacent to them. Don't expect any great deals

There is a liquor store next to Costco that sells Whiskey, it's not sold inside Costco. They also said the store is not owned by Costco.

The liqour store rightout side is owned by western beverarages.

there is a full liquor store.

At the Lewisville store there's a full liquor store out front

Yes the liquor store

Yes

Yes the liquor dept outside the main store