Those are large animals. They were very close to me. I'm sure you will still be impressed when I tell you I took the picture from my car.
The audio was spectacular. It's sort of like Morse Code. But the loudest Morse Code you have ever heard. Clicking back is ineffective to lure Prairie Dogs. Then again I could have been insulting them. If you are heading there from Denver you will have a short drive, a long walk, a broad view of the city, and animals large and small. According to google images you will even find some green.