Yeah, we're from South Dakota....I'll take some pics as we drive through western Nebraska. The Sand Hills are beautiful and in the summer LOTS of sunflowers. I do remember a rendering plant somewhere along the way, our eyes teared for awhile after THAT.  lol

....as for the critical, the only thing for me so far is this part:

"Although he didn’t understand, he now realized that the thing was somehow beckoning him. He doubted if that was entirely true, but it was most certainly how he felt."

THE ONLY THING I WOULD HAVE DONE HERE [caps to delineate]  I would have put something like: The coldness of the floor sent a shiver through him as he put his foot down. He wasn't sure if it was the actual cold or the anticipation of the machine.

"Kneeling beside it, he touched the machine’s cold, smooth surface, and he shuddered, feeling both menaced, and comforted by it. His hand slid up the side, feeling the flexible tubing, and then the round top, a cool glassy surface. The entire experience was almost hypnotic."

I write a completely different style, I would never be able to do the detail and intricacies that you have in your story. I'll try to be more critical, just not much in my nature.  :)