Were you going to answer the Rocky Mountains? The Himalayas? The Andes?
Turns out it’s neither of these. I wouldn’t have known that, mind you. I didn’t even know the relative length of any of those mountain ranges (4,800kms, 2,400kms, and 7,000kms, respectively, by the way). The record actually belongs to a mountain range that’s underwater…and stretches from Iceland, down under Africa, below Australia, up the Pacific to Baja California where it shoots up the west coast of the United States to end up in Alaska. Hawaii is actually the tip of this mountain range. It doesn’t have a name, but goes by ‘Mid-Oceanic Ridge’ (or ridges plural, depending on who you ask). It stretches 65,000kms!
Take two seconds to think about all that.
Now here’s a picture:
I learned about this from a very engaging book about the history of science (sort of) by Bill Bryson: A Short History of Nearly Everything. It’s not particularly scholarly, but wow is it ever a good read. Highly recommend.