You probably think Route 66 is the big one. It isn’t. Not even close. If you actually want to drive the longest road in the US, you have to look further north, spanning a massive ribbon of asphalt that stretches from the salty air of the Atlantic all the way to the Pacific Northwest. We are talking about U.S. Route 20. It covers 3,365 miles. That is a lot of gas station coffee.
Most people ignore it because it doesn’t have the flashy "Mother Road" neon marketing. But Route 20 is the real heavyweight. It cuts through twelve states. It starts in Boston, Massachusetts, and ends—or begins, depending on your vibe—in Newport, Oregon. It is essentially the backbone of the American landscape, yet somehow it remains a bit of a cult classic rather than a mainstream tourist trap.
Honestly, driving the whole thing is a test of endurance. You’ll see the finger lakes of New York, the endless cornfields of Iowa, and the terrifyingly beautiful peaks of the Rockies. It’s not just a highway; it’s a cross-section of everything that makes the country weird and wonderful.
Why U.S. Route 20 is the Undisputed Longest Road in the US
The math is pretty simple, but the history is a bit messy. Before the Interstate Highway System started cannibalizing everything in the 1950s, these "U.S. Routes" were the primary way to get anywhere. Route 20 was officially designated in 1926. Back then, it didn't even go all the way to the coast. It actually stopped at the eastern entrance of Yellowstone National Park. There was this big "gap" because, well, driving through a National Park isn't exactly high-speed commuting.
In 1940, the road was extended. Now, it technically "breaks" at Yellowstone and picks up again on the other side. This leads to some nerdy arguments among road-trip enthusiasts. Some purists argue that because the road isn't a continuous, unbroken line of pavement (you have to drive through the park on unnumbered roads to connect the pieces), it shouldn't count. But the Department of Transportation doesn't care about your technicalities. They list it as one continuous route. At 3,365 miles, it beats out U.S. Route 6 by about 160 miles.
Route 6 used to be longer, actually. It used to run from Provincetown, MA, all the way to Long Beach, CA. But in 1964, California got tired of the naming convention and re-designated their portion, lopping off a huge chunk of Route 6 and handing the "longest road" crown to Route 20.
The Coastal Start: Boston to the Midwest
Starting in Boston is chaotic. You begin near Kenmore Square, and immediately you're thrust into that aggressive East Coast traffic. But once you break free of the city, the road transforms into the "Jacob’s Ladder" trail through the Berkshires. It's old. It feels old. You’re passing stone walls that have been there since the 1700s.
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Then you hit New York. Most people think New York is just the city, but Route 20 shows you the "Upstate" reality. You’re rolling through the Cherry Valley, passing antique shops and places that sell maple syrup out of sheds. It’s scenic, but it’s also slow. That’s the thing about the longest road in the US—if you’re in a hurry, you’re doing it wrong. Take the I-90 if you want to go fast. Take Route 20 if you want to see the weirdest 20-foot tall statues in the country.
Pennsylvania and Ohio go by in a blur of industrial history and Great Lakes glimpses. You’ll hit Cleveland, then move into Indiana. Here, the road is often called the "Dunes Highway." You’re skirting the bottom of Lake Michigan. It’s flat. Very flat.
The Nebraska "Long Straight" and the Yellowstone Gap
Once you cross the Mississippi River at Dubuque, Iowa, the vibe changes. You’re in the heartland. This is where the scale of the longest road in the US really starts to sink in. In Nebraska, Route 20 is known as the Bridges to Buttes Byway.
Nebraska is misunderstood. People say it’s boring. They’re wrong. The northern tier of Nebraska, where Route 20 lives, is full of sandhills and dramatic bluffs. It feels like the Wild West hasn’t quite left. You’ll pass through towns like Valentine and Crawford. If your car breaks down here, you better hope you have a good book and some extra water. The distance between civilization starts to stretch.
Then you hit Wyoming.
This is the dramatic climax of the trip.
The road climbs.
The air gets thin.
You eventually reach the east gate of Yellowstone. This is where the "official" Route 20 signs disappear for a bit. You have to navigate the park’s Grand Loop Road. It’s a 50-mile gap of thermal geysers, bison jams, and tourists taking selfies too close to elk. Once you exit the West Entrance in Montana, the Route 20 signs reappear like an old friend.
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Why Route 66 Gets All the Credit (And Why It’s Wrong)
It’s marketing. Plain and simple. Bobby Troup wrote a song about Route 66. Pixar made a movie about it. Route 66 is the "Main Street of America." But here is the truth: Route 66 doesn't even exist anymore. Not officially. It was decommissioned in 1985. You can drive "Historic 66," but it’s a patchwork of frontage roads and interstate segments.
Route 20 is still a living, breathing federal highway. You can follow the shield from coast to coast.
Also, Route 66 was only about 2,448 miles long. Route 20 beats it by nearly a thousand miles. If you want the ultimate American road trip, you go for the length. You go for the 20.
Navigating the Pacific Finish
After leaving the Yellowstone area, you clip through a tiny corner of Montana and then head into Idaho. You’re crossing the Craters of the Moon area. It looks like another planet. Volcanic rock everywhere. It’s stark and beautiful in a way that makes you feel very small.
Oregon is the final boss. You have to cross the High Desert. It’s lonely. You’ll pass through Burns, Oregon—a town that defines "middle of nowhere." Then you hit the Cascades. You’re climbing again, through Santiam Pass. The forest gets thick, green, and wet. It’s a total 180 from the dry plains of Nebraska.
Finally, you hit Newport. The road ends at a junction with U.S. 101, just a few blocks from the Pacific Ocean. There is a sign there. It says "Boston 3,365 Miles." Most people take a photo and then go find a bowl of clam chowder. You’ve earned it.
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Practical Realities of Driving the Whole Thing
Don't try to do this in a week. You’ll hate your life. To actually enjoy the longest road in the US, you need at least 14 days. 21 is better.
- Fuel Strategy: In the East, gas is everywhere. In Wyoming and Eastern Oregon, "No Services for 80 Miles" is a literal warning. If you see a pump and you're under half a tank, stop. Just do it.
- The Yellowstone Factor: The park is closed to through-traffic in winter. If you try this in January, your "coast to coast" dream ends at a snowdrift in Cody, Wyoming. Plan for June through September.
- Small Town Sunday: In the Midwest and Plains, small-town America still shuts down on Sundays. Don't expect to find a local diner open in rural Iowa at 6:00 PM on a Sunday. You’ll be eating jerky from a Caseys gas station. (Which, honestly, is part of the experience).
The Evolution of America’s Longest Path
We often think of these roads as static lines on a map. They aren't. They shift. Bridges get rebuilt, bypasses get constructed, and sometimes the road actually shrinks or grows.
Back in the 1920s, the "Auto Trails" were a mess of competing private organizations. You had the Lincoln Highway and the Yellowstone Trail. Route 20 was created to bring order to that chaos. It absorbed pieces of these older trails, stitching together a path that had been used by wagons and cattle drives decades before cars existed.
When you drive through the Finger Lakes in New York, you aren't just on a road; you're on a corridor of Western expansion. When you cross the Missouri River, you’re following the same logic as the pioneers. The terrain dictates the path. The road just makes it easier.
Real Expert Insight: The Maintenance Nightmare
According to data from various State Departments of Transportation (like ODOT in Oregon and MassDOT in Massachusetts), maintaining a road this long is a logistical nightmare. Each state is responsible for its own section. This is why the pavement quality changes the second you cross a state line.
You’ll notice that some states, like Iowa, take immense pride in their section of Route 20. They’ve spent billions turning it into a four-lane divided highway across the entire state to support trucking. Other states keep it as a winding, two-lane country road. This inconsistency is what makes it "human." It’s not a sterile interstate experience where every mile looks like the last. It’s a reflection of the priorities of the people living along it.
Critical Next Steps for Your Road Trip
If you’re actually planning to tackle the longest road in the US, don't just wing it with Google Maps. Google will constantly try to redirect you to the Interstate because it thinks you want to be "efficient." You have to fight the algorithm.
- Buy a physical Rand McNally Atlas. You will lose cell service in the mountains of Oregon and the plains of Nebraska. Relying on GPS is a rookie mistake.
- Download the "Roadtrippers" app. Use it specifically to find the "muffler men" and oddball museums along Route 20. There is a Shrine of the Grotto of the Redemption in West Bend, Iowa, that you absolutely cannot miss.
- Check the National Park Service (NPS) alerts. Since Yellowstone is the literal middle of this journey, you need to know if there are road closures due to "bison jams" or hydrothermal activity.
- Book your Cody or West Yellowstone lodging six months in advance. This is the bottleneck of the entire trip. If you don't have a spot to sleep near the park, you’ll be driving an extra three hours out of your way.
The road is long. The car will get messy. You will probably get sick of fast food. But standing at that sign in Newport, Oregon, knowing you just tracked the entire width of the continent on a single highway number, is a feeling no interstate commute can ever give you.