My experience at Starved Rock goes back about 50 years.
My brother, a few friends and I camped there.
We took a shower one night under the waterfall (illegal, I know, but we were unsupervised kids). We also got "adopted" by a family camping nearby, who invited us to their dinner, and more importantly introduced us to the wild game called "spoons."
We went on a Ranger-led hike, with the ranger pointing out all sorts of plants and trees. At one point the ranger said: "In all the hikes I've led, no one has ever been able to identify this tree. I'll bet $1 million dollars that nobody here knows what this tree is!" One of my buddies yells out "Hophornbeam!" We started making fun of him, as we had never heard this word before. The Ranger sheepishly admitted that yes, it was in fact a Hophornbeam tree, or Ostrya Virginiana its scientific name. Sadly, my friend didn't get to collect the $1 Million.