Primitive Cave Drawings, Here?

I mentioned the other day something odd about seeing some primitive cave drawings on one of my latest adventures. Well, it's completely true! I found them in what may seem to be the most unlikeliest of places too! I would have never expected something so strange in such a place as this! Let me explain what happened.

There is a nature park I learned about last year while looking for geocaching sites on the web. It happened to be amazingly close to my home, so I knew I had to go there. Another nature park is always welcome for an everyday adventurer. The only problem was that when I got to the approximate location I could not find the park at all!

I saw what looked like a path going down under the road, but this was from a very busy highway with no parking for a very long ways. So there was no way to be sure the place was even there. I went back home and searched the web for a way in, but found nothing whatsoever.

Finally, about a week ago I found some better directions on the web. I drove to where I hoped to find this place the very same day. It turned out to be on the other side of the highway all along! And here it is, a place called Valley Woods Trail. It's a trail that goes along a quiet river, but surrounded by the hustle and bustle of urban surroundings in Southfield, Michigan.

I decided to take to the left of the trail when I got down the slope into the park. I figured it wouldn't go very far that way, so I would get it out of the way first. It was shorter than the other direction, but it was much longer than I expected. I may have walked at least a half mile.

I soon went around a bend and discovered that this trail went directly under the highway from where I had been searching. This highway is called Telegraph Road for any of you who might be curious. A very well known road in these parts. And that path I previously thought was the entranceway into the park was indeed a way down there! But let's get on to what it was that I found...

When I got under the highway, I felt like I really was in a cave or a tunnel. I have to say that even though I was so near such a busy highway, I didn't really hear the traffic very loudly. The acoustic nature of this park seems to muffle all of the noise very well.

It was when I looked to my right that I discovered something odd!

There it was! A drawing of a buffalo! Just like a caveman might make! This buffalo looked to be stenciled to perfection on the side of the support wall under the road. Just like when looking at a cave drawing, I wondered who put this there and why they did it. To me, it was just plain fascinating!

But that wasn't all!

A few feet farther down the tunnel there were more cave paintings. This time it was caveman style drawings of humans, and they were carrying axes. Three of them, and they were all different colors this time. Was this done to enhance the fun of the nature trail, or was it just graffiti put there by amused kids? Either way, it was an excellent idea.

Looking at the drawings from a little bit farther away, you can see that the cave dudes actually appear to be chasing the buffalo. I guess that is just like what a caveman might draw too, isn't it? The whole idea that someone would put these drawings here is interesting and humorous and fun all at the same time!

But I wonder... How long ago was this done? Who were the artists? And what became of them? And will those cave dudes ever catch that buffalo?