A 61-year-old tradition: How and why Chicago dyes the Chicago River emerald green

In February 1962, John Glenn became the first American to orbit the Earth.

Just over a month later, Chicago noted another impressive accomplishment — dyeing the Chicago River green for St. Patrick’s Day.

In the past 61 years, dyeing the river green has become a well-known tradition despite pushback from environmental groups. .

It’s happening again Saturday, a few hours before the start of the downtown Chicago St. Patrick’s Day parade, sponsored by Chicago Plumbers Local 130.

Plumbers are dyeing the Chicago River green at 10 a.m. The best places to watch are near Upper Wacker Drive and North Columbus Drive, according to the union.

How do they dye the Chicago River?

The dye comes, ironically, in the form of an orange vegetable-based powder that’s mixed by boats into the river.

Two families who’ve volunteered to dye the river for decades — the Butlers and the Rowans — have kept the exact recipe a closely guarded secret. Butler family patriarch Mike Butler would hide the canisters in the garage after picking them up every year, his daughter told a Sun-Times reporter writing about Butler.

He promised before he died in 2016 that he’d “take it to my grave.” However, the Rowans also knew the source.

“We always refer to it as ‘leprechaun dust,’” said Tom Rowan. “We have never told anybody what it is.”

The Rowans and Butlers figured out the best way to distribute the dyeing powder was by shaking it through old-fashioned flour-sifters. Then came the next step, a second boat — “the ‘Mixmaster,’” Marlene Butler, Mike Butler’s wife, told the Sun-Times in 2016.

As soon as it mixes with water, the orange dye turns a phosphorescent green.

“If you blow your nose, it’s green, and if you cry, it’s green,” one volunteer told the Sun-Times in 2012.

Why did they start dyeing the river?

Chicago’s river-dyeing tradition began in 1962, though the exact genesis of the idea is a bit murky. Most versions lead back to the sponsor of the St. Patrick’s Day parade — the Plumbers Union.

Mayor Richard J. Daley, who was from the working-class Irish neighborhood of Bridgeport, “wanted something spectacular” for the holiday, according to Marlene Butler.

A light-bulb moment happened when somebody spotted a plumber splashed with green stains from a substance used to check for leaks, she said. The color was a perfect fluorescent color, reminiscent of the shade associated with the Emerald Isle and Irish Catholicism.

Daley and Stephen Bailey, a Daley ally and powerful business manager with the Plumbers Union, at first toyed with dyeing Lake Michigan. Instead, they settled for the river.

After the first dyeing in 1962, Bailey told gathered reporters: “The Chicago River will dye the Illinois, which will dye the Mississippi, which will dye the Gulf of Mexico, which will send green dye up the Gulf Stream across the North Atlantic into the Irish Sea. A sea of green surrounding the land will appear as a greeting to all Irishmen of the Emerald Isle from the men of Erin in Chicago.”

Is the dye harmful?

Conservationists have pushed back on the tradition for years, including in the opinion pages of the Sun-Times. One letter-writer from Portland, Oregon told the Sun-Times in 2017 that, “it is an annual humiliation of a river.”

Leaders of Friends of the Chicago River, Openlands and the Illinois Chapter of the Sierra Club noted in a 2021 letter to the editor that the Chicago River has changed dramatically since 1962. During Daley’s time, the river was nearly dead, with only a handful of species of fish left in it.

But the river’s health has improved since then. There are more fish and wildlife living in it who could be harmed by the dye, the groups say.

“Regardless of whether the green dye is harmless — and we honestly don’t know, because the ingredients of the dye are a closely guarded secret — it’s time to rethink how the Chicago River is being treated,” the groups wrote. “It’s time to start seeing it for what it truly is — a wondrous natural resource as worthy as Lake Michigan of being improved, protected and respected.”