Is the world's longest unguarded border between Canada and the USA a myth?

It’s guarded in a couple of places where there are roads. However, if you go up in North Dakota or any of those norther states (Washington, Idaho, Montana, Minnesota, etc.) there are literally hundreds of miles where the US state and the Canadian province are separated by a fence, if that, but no humans around.

Even with no one around, there are sensors monitoring the area. That is why the border is mowed. Macom made the microwave transmitters and receivers.
I wouldn’t try it.

Yes, it is a myth. Go to the boarder crossings. You will find both US and Canadian crossing guards there.

Hardly the world’s longest unguarded border. Anyway, the Canadian-US Border is effectively guarded. Where there are no humans, there is radar and electronic and air and satellite surveillance. If you cross into Montana, for example, somebody somewhere will know about it. Whether or not they initiate pursuit is the question. God forbid if someone brought in some Cuban cigars or filled a prescription at a fraction of US cost. And then we have to protect ourselves from all those poorly educated, poverty stricken, Molson-swilling Canucks clamoring to get in to pursue a better life and healthcare. And that bloody aggressive military—gotta watch out for them.

Sudan’s borders are a total of 4,200 mi. and there is no way they can guard them effectively. But they don’t have to. People are trying to get out, not get in. If a rich country like Sweden can’t effectively guard their borders, no way can poor old Sudan—and I believe there are even longer unguarded borders in the world.

There is guarded, then there is GUARDED. How many military outposts do you see there?

The truth is that the “unguarded” part merely means that there is no military presence at the border. Look at the Mexican border and you see some military, and if you check the borders of North Korea you’ll see quite a bit, but the border between the US and Canada is secured solely by civilian authorities.

You can look at the border in Waterton – Glacier Internationa Peace park. When you are on the water you can easily see the border.

Here is a description of Transboundary protected areas.
Here is a picture of the boundary as it passes through Waterton – Glacier International Peace park.

I live near the shore of Lake Ontario. The US – Canadian Border passes by my place about 20 miles into the middle of the lake. Border Patrol agents cruise by here every day. They even know many of the people on the road. One time an agents found and let my neighbor’s dog into her house when it ran away. She was still out back looking for the dog and returned home all dejected to find the happy surprise.
We like our BP guys. They are friendly and helpful. If your car is stuck in snow they are willing to help pull you out.
There is not much action here.

One time I spotted a vehicle driving at night with no lights on in the wildlife management area. I went after it and blocked his escape with my Tahoe. It was an agent on patrol. He knew what I was doing and I understood what he was doing. We still wave to each other and smile.