The Chinook is a rare breed of sled dog that was developed in America in the early twentieth century by Arthur Walden, who wanted a new working dog breed that would make a good sled dog and a great family pet. Walden crossed a mixed bred Northern Husky/Mastiff type dog named Chinook with Belgian Sheepdogs, German Shepherd Dogs, Canadian Eskimo dogs and other breeds. His offspring were then bred back to him to develop the Chinook breed. In 1965, the Guinness Book of World Records recorded the Chinook as the rarest breed, with only 125 dogs alive. Breeders of Chinooks were so rare that in 1981 there were only 12 breedable Chinooks, however, the breed was kept from extinction through breeding programs existing in Maine, Ohio and California. The breed was registered with the United Kennel Club in 1991. Today, the breed is still a very rare, predominantly American breed.