When Jerry Dobson moved to Kansas in 2001, he was bombarded with questions and quips about the "flatness" of his new state. He had spent his life in the mountains of Georgia and Tennessee, so he had been used to dramatic topography.

So when Dobson arrived in Kansas, he "expected it to be flat but looked around and saw hills," he told National Geographic.

"And the more I studied, the more I realized the Great Plains as a whole are not as flat as people think," said Dobson, a professor of geography at the University of Kansas in Lawrence and the president of the American Geographical Society.

In fact, a lot of states aren't as level or as hilly as we are inclined to think. Yet, as Dobson has come to see, human perception turns out to be a valuable tool in assessing just how flat a place is.

View Images Horses graze in the Flint Hills of Kansas. PHOTOGRAPH BY JIM RICHARDSON, NATIONAL GEOGRAPHIC

This week Dobson and Joshua Campbell, a Ph.D. candidate who is now a geographer for the State Department in Washington, D.C., published a study called "The Flatness of U.S. States" in Geographical Review, a peer-reviewed journal published by the American Geographical Society. In it they listed the top five flattest states.

Kansas wasn't one of them. The flattest state is Florida. The most mountainous state? Well, it isn't Colorado. It's West Virginia.

The inspiration for Dobson's research came as he drove across Kansas with a GPS transmitter on his dashboard. "The first 300 miles [480 kilometers] is hilly, and the last 150 miles [240 kilometers] is truly flat," he said, with a caveat: "You are on an interstate and highway planners tend to choose the flattest land."

It's hard to change the state's topographical reputation. In 2003, a scientific "study" was published in the satirical Annals of Improbable Research that concluded that Kansas was literally flatter than a pancake.

All the hubbub prompted Dobson to ask his graduate students to investigate precisely why people think Kansas is so flat. Answering the call was Joshua Campbell. What the two geographers came up with is enough to make you think up is down. If you are convinced you live in a pancake state or a triple-decker burger state, you are possibly mistaken.

View Images The sun sets over the prairie near Manhattan, Kansas. PHOTOGRAPH BY JIM RICHARDSON, NATIONAL GEOGRAPHIC

Measuring "Flatness"

The first thing the researchers tackled was a basic question: How is flatness measured? The key problem is that there are many ways to measure that concept.

"A general tilt of the land does not affect human perception that much, but it can skew a mathematical analysis," said Dobson. That is why many people think of Kansas as flat, he thinks, even though the state gradually rises from an elevation of 679 feet (207 meters) in the east to 4,039 feet (1,231 meters) in the west.

Some people can't handle this fact and challenge the methodology. "A few people say the results can't be right because a given state has such-and-such highest point and such-and-such lowest point, but that's relief, that's not flatness," says Dobson.

"Flatness is how you perceive the ground as you are walking on it, driving on it, or standing on it; it's what people are talking about when they come here and say, 'This part of Kansas isn't as flat as I expected it to be.'"

View Images Florida's wetlands are part of the flattest state. PHOTOGRAPH BY HOBERMAN COLLECTION, UIG VIA GETTY

To measure the human-scale perception of flatness, Dobson and Campbell analyzed data from the Shuttle Radar Topography Mission in geographic information systems (GIS) software. They developed an algorithm that would approximate what a person would see if they were standing in one spot and then turning around in a circle, recording their view of the horizon 16 times in a revolution. Each segment was recorded as not flat, flat, flatter, or flattest.

The geographers analyzed all the land across the 48 contiguous U.S. states and the District of Columbia. They opted against including Alaska and Hawaii because they knew neither would be very flat.

The algorithm had to run for six days to process all the data.

View Images West Virginia has many rugged areas. PHOTOGRAPH BY SHAHID DURRANI, NATIONAL GEOGRAPHIC YOUR SHOT

Surprising Findings

Based on their own on-the-ground experience, Dobson and Campbell, who hails from southwest Kansas, predicted that Kansas would not be among the top five flattest states. They were right. It took seventh place, behind Florida, Illinois, North Dakota, Louisiana, Minnesota, and Delaware.

In fact, Dobson and Campbell had correctly predicted that Florida would be the flattest state, based on their knowledge of its geography. They also predicted that other states with large coastal plains, like South Carolina and Delaware, would prove to be very flat.

They whiffed. Dobson was surprised that South Carolina ended up ranking 15th in flatness and that Delaware was as low as sixth.

"One that really surprised me was Louisiana," adds Dobson, who explained that he hadn't expected it to turn out to be so flat. It was the coastal plain and the wide, flat plain of the Mississippi River Basin that made the difference, he says.

The least flat state, West Virginia, also surprised the researchers. Although the state's nickname is the Mountain State and its flagship public university's athletic teams are called the Mountaineers, Dobson says the researchers didn't expect the data would confirm the nicknames to that degree.

Other states that are commonly thought of as mountainous included Vermont (45th), Colorado (25th), California (24th), and Utah (23rd).