A mystery Powerball winner has won a $768.4 million jackpot in Wisconsin.
But the lucky person hasn't come forward yet, Wisconsin Lottery Director Cindy Polzin said at a news conference Thursday.
"Get your affairs in order," Polzin urged, adding, "you have 180 days to claim your ticket here in Madison. So we certainly look forward to meeting you."
(MORE: $1.5 billion Mega Millions winner decided to buy ticket while on a 'scenic drive')The jackpot -- the third-largest in U.S. history at $768.4 million -- has a lump sum cash value of $477 million, according to the Powerball website.
The winning ticket was sold Wednesday at a Speedway in New Berlin, about 15 miles west of Milwaukee.
State law does not allow the winner to stay anonymous, she said.
"We ask them to please sign your ticket," Polzin added. "Take ownership of that ticket."
(MORE: Powerball jackpot inches closer to a billion dollars with no winner)The numbers drawn on Wednesday were 16-20-37-44-62 and a Powerball of 12.
The retailer that sold the winning ticket will also receive $100,000.
"This is an amazing milestone moment for Wisconsin," Polzin said in a statement Wednesday. "It truly is incredible to think that the winning ticket for this historic jackpot was sold in our own backyard. I am extremely excited for the winners and for our state."
(MORE: Breaking down the odds of winning Powerball's $700M jackpot)The jackpot was the first win of this year.
Despite how high the jackpot climbs, players' odds of winning stay at same at 1 in 292 million, according to Powerball.