It's time to turn Chicago green for St. Patrick's Day.
According to a blog post from Choose Chicago, the Chicago River dyeing, which is typically held the Saturday before St. Patrick's Day, along with the city's St. Patrick's Day Parade, dates back more than half a century.
"The first time the Chicago River was dyed green was in 1962, thanks to a suggestion from the local plumbers union," the post says. The post goes on to say that while the first dyeing turned the waters of the Chicago River green for nearly a month, the dye now only lasts a few hours.
This year, the Chicago River will be dyed green beginning at 10 a.m. on Saturday, Mar. 11. At that time, green dyed will be dumped into the Chicago River between State and Columbus.