Colorado's Secretary of State now has to verify 68,000 signatures to get a gambling initiative on the ballot.
If passed, dog tracks in Colorado Springs, Loveland, Commerce City and Pueblo could apply to have video lottery terminals that look like slot machines in their establishments.
Other places include the horse track in Arapahoe County, and the current gambling towns of Cripple Creek, Black Hawk and Central City.
The initiative also sets aside $25-million a year to promote Colorado tourism.
The group has turned in 120,000 signatures for this initiative.