Canadians have been flocking across the border to buy lottery tickets as the U.S. prepares for its biggest jackpot draw ever.

Lotto fever has gripped Canadians hoping to cash in on the $1.6 billion U.S. prize ($2.1 billion in Canadian dollars), with the winning numbers drawn tonight.

Those who rarely make a trip south have decided to make an exception and go in search of lady luck and the chance of winning the huge sum.

Gas station clerk Becca Silvas in Blaine, Wash., told CTV News that some customers are spending up to $100 a time on 20 tickets.

“In one transaction they’re spending 80, 90 or 100 dollars,” she said.

“It's really increasing the amount of customers we're having in here.”

The Mega Millions has rolled over 25 times causing the prize to balloon.

And another jackpot, The Powerball, has gone unclaimed leaving a further $620 million up for grabs on Wednesday.

Ric Lafayette from Langley, B.C., said he needed to come down to try to win that $1.6 billion.

“That’s definitely worth a trip across the border for me,” he said.

Another Canadian, who hadn’t been south of the border in eight years, decided it was time to get gas and buy a ticket too.

With so many being snapped up, the likelihood of the prize being rolled over again are slim.

And the odds of winning are even slimmer – one in 302 million.

---- With files from CTV Vancouver’s Angela Jung