I ran across this marker on Green Bay Road at its intersection with Lake Cook Road and Indian Tree Drive in Highland Park. It looks like the old stone mile markers from the 1920's I used to see as a child in New Jersey, and more recently from Houston, Texas as posted on that city's biggest internet form, HAIF. It seems to be in remarkably good condition, if it was actually erected in 1927 as I suspect.
Carved into the face of it is
1927What those numbers mean, I don't know. Here's a picture of the location where I stumbled across it, to give it some context. If you have any idea what it's for, leave a note in the Comments section below.