Clue 1: the horizon is really flat. And there's lots of corn. Not only at this Champaign-Urbana farmer's market, where the corn is stacked as high as a child's eye, but also stalking in the fields – along with soybeans aplenty.
Clue 2: when the husband of your wife's sister, Jerry (reaching out for corn in the photo above) tells you that a subdivision is going to replace a corn field near their house, and you say, "But isn't that zoned farmland?," after which he smilingly reminds you that you're not in Oregon anymore, which still has some good land use laws that protect corn and other vegetative living things even after Measure 37, in contrast to most other unenlightened states of the union.
Clue 3: you get off an airplane and you don't hear harp and piano music playing in concourses anymore; nor are your surroundings bright, cheerful, clean, and well-designed; and you have to search hither and yon for a hint of the healthy food that is so readily available at the airport you left from, which happens to be Portland, and appears to be banned at your not-quite-final destination, Chicago – along with any paint that isn't gray, black, or otherwise depressing.
(Portlanders, there may be some things to complain about as regards your town, but your airport is not one of them. Further, speaking as a Salem resident, be thankful you have an airport with planes that go more places directly than just Salt Lake City – our one and only non-stop destination choice.)