(CNN) -- The new parlor game gripping two cities a thousand miles apart -- "Who Won the Powerball" -- ramped up Friday amid rumors, speculation and tantalizing clues.
In Missouri, the rural, 500-resident town of Dearborn was buzzing with speculation ahead of a scheduled 12 p.m. news conference with lottery officials at a high school to announce what the agency called "the winners" of the Show Me State share of the record-setting Powerball jackpot.
While the agency seemed to hint at the possibility of a group win, Kansas City area media outlets were reporting the winning ticket is held by a 52-year-old Dearborn man named Mark Hill.
"It was us," Hill's son, Jason Hill, quoted his dad as saying in announcing the win to the family, reported CNN affiliate KCTV.
"I hope we all stay very grounded, stay humble and don't forget who we are," he told the station.
Missouri Lottery officials have not yet confirmed the identity of the winner, who will get half of the largest Powerball jackpot ever, $587.5 million.
The question of who won the Arizona jackpot -- sold at a convenience store in Fountain Hills -- took an interesting twist Thursday when a man walked into an Exxon gas station in Upper Marlboro, Maryland, to casually check a stash of lottery tickets.
"I got it!" acting manager Negassi Ghebre said the man shouted after checking the tickets against the winning numbers.
"Then he showed us the numbers, and the numbers were right, they matched," he told CNN.
Before that development Thursday, the manager of the Four Sons Foods Store in Fountain Hills said he hoped he was manning the register when the winning ticket was sold.
"Unbelievable," manager Bob Chebat said. "Everyone comes in here buying tickets, joking they'll take care of you if they win. But chances are so slim that it becomes standard that no one does win. I just don't know what to say. I'm shocked. I hope I was the guy who sold the winning ticket."
Back in Missouri, clerk Kristi Williams, at the Dearborn Trex Mart where that state's winning ticket was sold, asked every customer the same question Thursday: 'Have you checked your ticket?' " she told CNN affiliate KCTV of Kansas City.
The Arizona store will receive $25,000 for selling the winning ticket, while the Missouri store will get $50,000. The payout to sellers varies state to state as it is determined by each state's lottery officials.
The prize for the lottery -- held in 42 states, the U.S. Virgin Islands and the District of Columbia -- swelled to the largest in Powerball history after the jackpot rolled over 16 times without a winner.
It still doesn't match the U.S. record payout of $656 million, set in March by a Mega Millions jackpot. Three winners split that pot.
California added its name Thursday to the states participating in Powerball, with the California Lottery Commission voting unanimously to adopt the mega-jackpot lottery game. Powerball tickets will go on sale in California on April 8, 2013.
Lottery officials previously urged winners to take their time coming forward.
Winners should sign the ticket, put it in a safe place and seek legal and financial advice before redeeming it, Missouri Lottery Director May Scheve Reardon said.
Whoever comes forward with the winning tickets may want to speak to Donald Lawson. The Michigan man won the $337 million Powerball prize in August and vowed that the new infusion of green would not change him -- or his eating habits.
"I'm a millionaire now, but I'll still go to McDonald's," he said as he stood smiling at the Michigan Lottery headquarters in Lansing.
Back in Dearborn, resident Bill Matney said he hoped the winning ticket holder didn't "get deluged by a lot of people wanting part of their winnings."
"And that they put it to a good use like charity," he told KCTV. "I mean, who can spend that much money?"
CNN's Shawn Nottingham and Kyung Lah contributed to this report.
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