Illinois is flatter than every state but one, according to researchers, and is less hilly even than Kansas, a place once proven to be flatter than an IHOP pancake.



Jerome Dobson, a University of Kansas geographer, set out to compare how flat states actually are with how flat people think they are. In a 2013 survey that asked Americans which state is flattest, a full third of respondents guessed Kansas. But Dobson's team found that Florida, with its low-lying coastal plains, was the flattest of the 48 contiguous states and Washington, D.C.



"That makes the interesting question, 'What's second?' " said Dobson, who is also president of the American Geographical Society. "I know that the flattest place I've ever seen is central Illinois."



Dobson was right, finding half of Illinois to be flat by using a formula that broke states into small sections and then analyzed the elevation data in those plots. Illinois beat out North Dakota, Louisiana and Minnesota for the distinction of being America's second-flattest state. Kansas, despite its reputation for hill-less plains, was merely the seventh-flattest. West Virginia was the least flat.



The Land of Lincoln's topography, or lack thereof, is due to a series of glaciers that receded from the state tens of thousands of years ago, scientists said.



"Illinois owes its flat land to glaciation," said Richard Berg, interim director of the Illinois State Geological Survey. "That's why we have some of the best farmland in the world – It's flat."



Dobson, the lead author of the article published earlier this year in the Geographical Review, said his study proves that perceptions of flatness don't always add up to actual flatness. He co-wrote the article with Joshua Campbell.



Dobson cited the "bleak farm" Dorothy and Toto were swept away from during "The Wizard of Oz" as one reason people might perceive Kansas as flat. He also suggested that cross-country travelers see a lot more of flat Kansas, which is wide but fairly short, than they do of tall, narrow Illinois.



About 10 years ago, a study jokingly compared Kansas' topography to that of a pancake and found the state to be flatter than the breakfast entree. The methods were valid, Dobson said in his article, but any state would be flatter than a pancake if the flapjack were expanded to the size of a state.



Still, the popular notion of Kansas' flatness permeated even the most educated minds. Berg, the Illinois geologist, said he would have guessed Toto's homeland to be the flattest state in the Midwest.



"I would have probably said Kansas," he said. "But actually Kansas has some rolling hills and it's not as flat as you think."



Dobson's study didn't examine data from Hawaii or Alaska, but he said neither would have been among the country's flattest.



And with the proof now in his paper, the professor said Kansas can bequeath to Florida and Illinois the "dubious honor" of being flatter than anywhere else.



But Berg said the benefits of flatness, especially the rich agricultural land the glaciers left when they smoothed the state's geography, makes him think Illinois should embrace the label.



"I don't think it's a problem," he said. "Especially given some of the other titles we've had."



mitsmith@tribune.com

Twitter @MitchKSmith



