An employee closing Trig's Minocqua Shell for the night mistakenly entered the price of a gallon of gasoline as 32.9 cents instead of $3.299 on Monday night.
He left about 10 p.m., but drivers could still use their credit cards to buy gas.
Word of the bargain spread fast in the rural northern Wisconsin community, with 42 people buying 586 gallons of gas in an hour and 45 minutes. One person had pumped 27 gallons and two purchased 18 gallons.
Local police saw the horde at the station and called store manager Andrea Reuland, who went to the station and pushed the emergency stop.
"There were cars two deep at each of my pumps," said Reuland, who knew many of the drivers and told them they were being dishonest - the main store sign had the correct price.
"I was very upset that there's that many dishonest people," she said. "They knew there was a problem, and they took advantage of an employee's mistake and I think that's terrible."
The employee, who has been there for about six months, had changed the gas prices 25 times in the past six months.
"It was an honest mistake," Reuland said. "I could have done it."
Area residents were still talking about it Friday morning.
"Was it you guys?" a woman in the station asked Reuland. "Why do I always miss the good stuff?"