The Monsters of Millwood County

You pick up the red and orange bag, the fabric coarse on your hands as you search for a zipper. You unzip the front two pockets and find nothing of value. You open the final section and look inside, finding a few notebooks. They appear to be school notes, studying a subject far, far above your level of expertise with complex formulas and the like.
That is until you get to a page with a very lovely drawing. It's a pencil sketch of the surrounding area, with shading and detail that would make many an art student envious. There is, of course, one major difference.