Here's the picture from the top of the article. Notice the dourthouse in red.
How here's an overhead shot of the same area.
The courthouse is off the picture in the direction of the arrow.
The stage must be at the right hand side of the picture where the red line is.
Where are the 8? lanes of traffic in the top picture that are in the red square in the bottom picture>
What makes you think that the rally wasn’t held on the open area on the left side of the roadway as viewed in your pic @ 113?
The crowd isn’t past the highway. The arch grounds slope up a hill - it just looks like it extends back to the court house.
You should remember that I-70 is below the level of Memorial Dr. So you wouldn't see it. Also, note how there is a "line" at the rear of the crowd...it doesn't just taper off. That also indicates a boundary. The flag on the background appears to be hung from a scaffolding used to hold lights or speakers.
As much as I'd like to bust the picture, it appears legit.