In a stretch of the United States disparagingly called “flyover country,” writer Porter Fox took the long way.

Instead of flying over the Great Lakes and other waterways in the heart of the country, he floated on them last summer in a 740-foot freighter, from Montreal to Thunder Bay. For six days, as he inched across the lakes at around 20 miles per hour, he had some insights about the Great North along the way.

Fox’s epic journey — from his native Maine to Minnesota’s Boundary Waters to the Pacific — was research for “Northland,” his forthcoming book on the northern border of the United States. Now back home in Brooklyn, he talked to us about why Minnesota is the real backcountry, the color of Lake Superior and “slow travel.”

Q: What did you hope to find on your trip?

A: I was looking for similarities along the way. Things that I had seen in Maine, I would start to see in Minnesota. Things I had seen in Montana, I remembered also seeing in upstate New York — really cool demographic and geographic areas that you really would never put together.

I saw in Maine the name of a bar, the Northland bar, Northland real estate. I get out to Ely, and there’s the Nord Lund auto mechanic shop, the North Country outfitters. They use a lot of the same vocabulary.

Porter Fox

Q: Did you find those similarities in the people, too?

A: There’s something about living with your back to the border in the far reaches of the northern part of the country that attracts a similar type of person. There’s a real homesteading culture up there. There are very strong ethnic groups where people all lived together and retained their cultural ties.

Q: You saw four of the five Great Lakes. Did each lake have its own character?

A: Very much. A lot of that character is determined by weather conditions. Lake Erie is very shallow and has kind of a muddy color to it, and the waves get really big even in a moderate breeze. And then Superior is just an ocean. It’s deep, deep blue and the cliffs around the shoreline are hundreds of feet tall. The weather there is pretty fierce. It was just a very different beast from all of the other lakes.

On the route on the other lakes, you could typically see the shoreline somewhere. But on Superior, you just couldn’t see anything. It was just water everywhere.

Q: What was your impression of the Boundary Waters?

A: Omigod, incredible. It was infinite. You could never in a thousand lifetimes explore every corner. I couldn’t believe how many lakes we went through, how many miles we covered. It was so enthralling to just pick up your canoe, walk 100 yards, put it back in, and it looked like you were in an exact replica of the lake you were just in. It just goes on and on.

I thought I grew up in the backcountry in northern Maine, and I realized the real backcountry is out in Minnesota.

Q: “Slow” is a trend — “slow food,” “slow television.” Is what you did “slow travel”?

A: It was, and to be perfectly honest, it wasn’t purposeful. I just wanted to travel along the border and see the Great Lakes lifestyle. And my first two hours on the ship, I realized, “Omigod, this is really slow.”

There was a definite panic at first, because I’m so used to flying and driving and being able to pull off and grab a hotel room or go catch a movie. But over the course of the first day or two, you slip into this meditation. By the end of it, I would be sitting in the wheelhouse for three or four hours, not speaking to anyone. It’s mesmerizing. Literally inch by inch, just crawling across America.

Q: Had you spent much time on boats before?

A: My father was a boat builder and I grew up on sailboats. But when you’re a passenger and you’re not really dealing with the operation of a ship, you’re just sitting there watching the land go by. It took some getting used to.

Q: How does a freighter compare with, say, a cruise ship?

A: It’s just completely different. This is a trip for somebody who either has an interest in commercial shipping or has an interest in the lakes specifically — and wants some seclusion. The same person that would Airbnb a cabin out in the woods that you have to snowshoe to and can hole up there for a couple of weeks, that’s the mentality that it takes to enjoy yourself on one of these freighter trips.

There’s no customer service. There’s no party planner on the luau deck. You’re completely left alone. It’s not a time-efficient way to get from Point A to Point B, so it’s really about having some time away from civilization.

Q: Tell us about your book, “Northland.”

A: Really, what the book is about is defining this northern swath of territory in America that gets very little attention, very little press, and has been kind of hard to define for people.

Growing up in northern Maine, it’s kind of a one-way trip to the Northland. If you’re not going to Canada, you just turn around and go back. And people in America seem to want to traverse east and west and not get too far north.

Q: Are you still traveling?

A: I just completed my trip about two weeks ago. I walked the last 100 feet north of Bellingham, Washington. It took almost two years to do all of the trips. I canoed the U.S./Canada border in Maine; went overland through Vermont, New York and New Hampshire; did the freighter across the lakes; canoed through the Boundary Waters in Minnesota; and then went overland to Blaine, Washington, and got into sea kayaks on San Juan Island and paddled the border.

Q: When can we expect the book?

A: The book will be out in 2018. I’ll be doing a book tour and the whole gamut.

Q: Will you be doing it by freighter?

A: Uh, I don’t think so.