MOJO Marketplace is sponsoring the afterparty and it will be held at The Green Pig. This is a sports bar/pub located one block west of The City County Building. They will be checking your WordCamp badges at the door so they know you are with WordCamp (be sure to keep your badge). After this your appetizers and drinks will be covered. The building has a great rooftop patio for you to enjoy and mingle with other attendees. The afterparty will start around 6pm. There will still be volunteers around if anyone has any concerns.
There is a map on the location page.