And, just days before Christmas, she got a call.
"I thought it really was from Publishers Clearing House," Elmstedt said. "I was so happy. I thought, 'Oh the things I can do with that money!'"
The caller told the 78-year-old she'd won $400,000 - and all she had to do was send a cashier's check for $2,200 to prepay part of the taxes, reports CBS News Correspondent Cynthia Bowers.
The claim sounded sincere, particularly since Ruth remembered seeing a Minnesota couple win the $10 million prize last year. So she let herself believe in a Christmas miracle.
"I was going to send it in. I called my bank and was making arrangements," she said.
Her bank got suspicious. So did her son, Gary - especially when the phone kept ringing.
"Each call they stepped up the pressure on her," Gary Elmstedt said. "Haven't you sent the check yet? How come you haven't? Don't you want to win?"
Sensing a scam, he called the Minnesota Attorney General's office. Within hours, the state phone bank had received a dozen similar complaints - including some where the brazen crooks even posed as IRS agents looking for sweepstakes tax money.
The flood of calls suggested a con team was targeting the state, using new tricks like prepaid calling cards to make the calls even harder to trace.
"That's very new. Very new. And a lot of these scams that we're seeing, the scams in and of themselves are probably old. But they follow the invention of technology," said Minnesota Solicitor General Lori Swanson.
Publishers Clearing House says it is working with law enforcement to track down these con artists, but stresses it never contacts sweepstakes winners by phone.
"If you receive a call from somebody saying that you've won a prize, if they are requiring money, hang up the phone, it's not a legitimate sweepstakes offer," said Chris Irving of Publishers Clearing House Sweepstakes.
And to make matters even worse, falling for this con could be just the beginning of someone's problems.
"These type of scam artists often don't stop at that particular check. Once they know your name and your address and your check routing numbers, they can use it to do all kinds of things to ruin your identity," Swanson said.
That would be enough to ruin anyone's holiday.