Katahdins have demonstrated wide adaptability. In cold weather, they grow a very thick winter coat which then sheds during warm seasons. Their smooth hair coat and other adaptive characteristics allow them to tolerate heat and humidity well.

They exhibit moderate flocking instinct. Some may give a herding dog a bit of a hard time. Their independent nature make them a good sheep for large operations.

Mature ewes usually have twins, occasionally producing triplets or quadruplets. A well-managed and selected flock should produce a 200% lamb crop.

The Katahdin ewe shows a strong, protective mothering instinct, usually lambs without assistance, and has ample milk for her lambs. Rejection of lambs is rare.

The hair coat of the Katahdin varies in length and texture among individuals and can be any color or color combination. It generally consists of coarse outer hair fibers and an undercoat of fine wooly fibers that becomes very thick and longer if cold weather sets in and day length decreases. This undercoat and some hair naturally sheds as temperature and day length increase seasonally, leaving a shorter, smooth summer coat. While some uses may be found for the shed fiber, it is generally not harvested.

The development of the breed began in the late 1950's with the importation of a small number of haired sheep from the Caribbean by Michael Piel of Maine. The Piel Farm had several thousand sheep at the time and Piel felt that "progress in selection for traits important to the production of meat would be greatly enhanced by the elimination of wool as a major factor for selection." His goal was to combine the hair coat, prolificacy, and hardiness of the Virgin Island sheep with the meat conformation and rate of growth of wool breeds. After almost 20 years of cross breeding in every conceivable combination" and selecting the individuals with the desired combination of traits, Piel eventually collected a flock of ewes he called Katahdins, named after Mt. Katahdin in Maine.