Missouri also has open container laws. But there are certain outside events that allow open containers within the confines of said events. St. Louis has one of the biggest Mardi Gras outside of New Orleans (at least that's what they say around here) and they do sell alcohol within confined areas for that event. There are also various fairs and the like, including the Scottish Games, that also allow it. It only becomes a problem, and illegal, when you leave the confined areas.