Discover the past of Chicago's emerald waters and the festivities that capture the spirit of St. Patrick's Day.

The Chicago River is once again glowing kelly green after the city opened its annual St. Patrick's Day celebrations. Video above: Chicago River turns green for St. Patrick's Day Thousands lined the river and packed bridges Saturday and erupted in cheers as members of the Chicago Journeymen Plumbers Union Local 130 sprayed dye into the water from boats,

While St. Patrick's Day isn't until Monday, Chicago's iconic tradition dyeing the river green is happening Saturday. Here is how to watch the event.