The first spontaneous mutation was part of an otherwise normal litter of kittens. The breed founders, Linda and Richard Koehl, owned a cherry farm in Oregon and had obtained some farm cats for pest control. One of these was an ordinary brown tabby shorthair called Speedy who gave birth to a litter of kittens which included a rather bald female kitten with tabby markings on her skin. The owners were initially concerned about the kitten's appearance but she developed healthily and as she grew she developed a soft curly coat.
The kitten was named Curly and given no special treatment, also working as a farm cat. Another key trait of the breed, the unusually affectionate temperament, was only fully appreciated after a particular incident took place. Curly was injured when she climbed into the warm engine of a pickup truck. She was injured by the fan when the engine was started. She survived and became a house cat for a while recovering from her injuries and it was during this time that the Koehls observed her affectionate personality. She became pregnant and gave birth to five kittens which had the same appearance as their mother had had at birth. All five were male and grew up to have the same curly or 'rexed' coats. None of the five were neutered and they were allowed to breed freely with the other farm cats.
This resulted in a growing colony of unusual 'rex; cats which included long and short coats. There were a range of colours and patterns including chocolate and colorpoints due to the input of a local cat who had a Siamese mother. When people started commenting on her unusual cats and asking what they were, Linda did some research and realised that she had some kind of 'rex'. She took some cats to a show to ask for feedback and was told by exhibitors. breeders and judges that she had something unique. Several key people in the USA gave her their support and the colony was used as the foundation for the breed, which has grown and become a well established championship breed around the world.