The tough little cairn terrier originates from the scottish highlands, just like the west highland white and scottish terrier, two breeds that it's closely related to. No one knows for sure where terriers originally come from, but they were mentioned as early as the 300's and were first kept as hunters, later also as farmdogs. Thanks to their small size they didn't need much food, and usually had to find it on their own. The brits called pretty much all of the varieties scottish or skye terrier, whereas the scots generally named the dogs after where the villages they came from. That's the reason the cairn terrier has sometimes been known as scottish terrier or shorthaired skye terrier.

The cairn is probably the scottish terrier breed that most closely resembles the original scottish working terriers. It was recognized in 1910 (before that it competed as a skye terrier), but was still sometimes crossed with the west highland white. Even to the 1960's, white puppies could sometimes be born in cairn terrier litters.
The cairn terrier should appear active, lively and with great endurance. The head is broad with a clearly visible stop. The muzzle is powerful but not long. The ears are small and pointed. The neck must not be short, and the body had a deep chest and straight back. The tail should be carried happily but not over the back. The coat is very important, long and scruffy without being overly coarse.