Traffic was backed up along Arizona 87, the Beeline Highway, almost two miles toward Fountain Hills.
Many started lining up on Monday and slept in cars or tents while waiting for their big breaks.
Melanie Shirk, 47, of west Phoenix, said that she needed "a life change" and "money."
"It's not like you need a brain to do this," said the waitress and single mother of three. "You just have to pick a number. Even the losers win hundreds of thousands of dollars."