The American Mammoth Jack is considered a Heritage Breed. Heritage Breed is a term developed by the Livestock Conservancy to describe various breeds of animals that were part of everyday life of our forefathers during the early days of the development of America. Breeds that were essential to the survival of generations past. These breeds include livestock as well as poultry breeds. The American Mammoth Jack is considered a Heritage Breed due to its use historically to pull plows and wagons on the farm.

As a result of the modernization of agriculture, Heritage Breeds have become less vital, which in turn has caused many of these breeds to become endangered. The Livestock Conservancy has classified the American Mammoth Jackstock as critical on their endangered list. Critical is classified as fewer than 200 annual registrations in the United States, and an estimated global population of less than 2000 individuals. Registrations with the American Mammoth Jackstock Registry have declined over the past several decades. New registrations with the AMJR are nowhere near 200 annually, although 2019 has seen an increase in registrations.

The American Mammoth Jackstock Registry is committed to maintaining the original characteristics outlined by The Standard Jack and Jennet Registry (SJJR) founded in 1888, which is now known as the American Mammoth Jackstock Registry (AMJR).