Yep, it’s true what they say: every St. Patrick’s Day, they dye the Chicago River bright green, using a powdered, vegetable-based dye that is harmless to fish. It’s orange when it goes in the water, and then turns, well, you’ll see. . .

I had to go downtown for shopping today, and when I saw that the usually empty Saturday morning train was full, and most of the people were wearing green, some with funny hats and shamrock-shaped antennae, I knew what I was in for. (Lots of them were already drunk by 10 a.m.; the parade follows the river dyeing.)

Here’s how they do it . The next three photos, sent by reader Joe Dickinson, were taken in 2006 and show the beginning of the dyeing, which starts at 9:15 promptly.

Back to my photos: the result at 10:10 a.m.:

I mean, it’s really green!

It was madness: around the Michigan Avenue bridge there were mounted cops to keep people in line, and they were shouting to people on the bridge, “Selfie and then move on!” Here’s a couple with the proper spirit (note the man’s green hair):

The mounted cops themselves were a tourist attraction. Here’s an Asian tourist using that most nefarious of objects: a selfie stick:

Finally out of the crowds, I saw two antlike figures on a nearby building:

They were window washers, and not on a platform, but suspended by ropes hundreds of feet above the ground. What a job!