The 20-cent Rainbow pick six jackpot was hit by 17 tickets on Thursday, resulting in a carryover of $436,836 for Sunday's closing day of the autumn meeting.
The bet must be paid out on the closing day, and the pool of new money may reach $3 million.
The Rainbow pick six covers the fourth through ninth races on a nine-race program that begins at 11:30 a.m., Pacific.