Holly Lahti, who is apparently from the small town of Rathdrum, will split the second-largest lottery jackpot in history with Jim and Carolyn McCullar of Ephrata, Wash.
Jim, 68, and Carolyn, 63, McCullar appeared at a news conference last Thursday to announce they'd won half the jackpot, or $190 million.
Lahti wasn't on hand for Wednesday's announcement in Boise.
"She's requested that the media respect her privacy and not attempt to contact her until she's prepared to speak to you," Lottery Director Jeff Anderson said at a news conference.
He referred to Lahti as a "delightful young lady" and said he tried to persuade her to go public because there are "a lot of curious people out there." But he said she has a lot to get in order first.
"We expect she'll be coming forward shortly," Anderson said. Lahti's age and hometown were not immediately released, but public records show she and her mother, Elaine C. Alford, live in Rathdrum, a town of about 7,000 people.
Nobody was home at Alford's residence Wednesday, but neighbor Eric Miller said Holly Lahti visits her mother almost daily.
Miller, 19, said he had no idea Lahti was the winner of the huge Mega Millions prize until he was told by a reporter.
"I want to go over there and be her friend now," Miller said laughing. "But she's really nice, very friendly."
Although Mega Millions is played in 41 states and Washington, D.C., the two winning tickets were purchased by people living in small towns just 125 miles apart in the Inland Northwest. Ephrata, Wash., has about 7,500 people.
The drawing was held Jan. 4, and residents began buzzing when they found out one of the winning tickets was sold in Post Falls, a suburban community of housing developments, big box stores and fast-food restaurants.
"Once people hear this, Ady's Convenience & Car Wash is going to become the luckiest place in northern Idaho," Anderson said of the store where Lahti bought her ticket.
The winners had to match five numbers plus the "Mega ball." The numbers were 4, 8, 15, 25 and 47, and 42 as the Mega ball.
The McCullars had played some combination of those numbers for years because they're based on the couple's birthdays.
Anderson said Lahti let the computer pick her numbers.
Lahti has claimed her winnings but not yet cashed in her ticket, he said. If she takes a lump sum payment, she would get $120 million before taxes. The federal government would take $30 million, while the Idaho State Tax Commission would take a $9 million slice, leaving her with about $80.7 million.
Ady's Convenience & Car Wash receives a $50,000 award.
Lahti is not the first Idaho jackpot winner to try and avoid the media crush and public attention. In 2005, Brad Duke of Boise sought to keep a low profile after winning a $220 million Powerball drawing. Duke assembled a team of lawyers and accountants and asked the Idaho Lottery Commission for complete anonymity.
But former Idaho Lottery Director Roger Simmons denied the request, arguing that state law and the integrity of the lottery required that his name be made public to show he had no ties to lottery employees or vendors.
Duke later appeared at a news conference in Boise and made several appearances on national television talk shows.
Miller reported from Boise, Idaho.