Idaho designated the native appaloosa as the official state horse in 1975. Most Appaloosas are distinguished by their colorful spotted coat patterns, striped hooves, mottled skin, and white sclera around the eye. The original appaloosas were highly regarded as hardy range horses. Idaho offers a custom license plate featuring an Appaloosa horse (Idaho was the first state to offer a license plate featuring a state horse).

Opinions vary on how spotted horses first arrived in America. Some believe they arrived with the Spanish Conquistadors in the early 1500s, others think Russian fur-traders brought them at a later date. Another theory is that large numbers were shipped to America when spotted horses went out of style in late 18th century Europe.

It is established that the Nez Perce Indians of the American northwest were known as exceptional horse breeders that had developed strict breeding selection practices for their horses. By the late 1800's they began to emphasize spotted color in their breeding program.

Appaloosas come in various base colors including bay, black, chestnut, palomino, buckskin, dun and grulla. The unique spotting patterns of the Appaloosa are described as:

Blanket - white over the hip that may extend from the tail to the base of the neck. The spots inside the blanket (if present) are the same color as the horse's base coat

Leopard - white pattern exhibited to an extreme with base colored spots of various sizes covering most of the body .

Few Spot Leopard - base color is nearly obscured by its Appaloosa white patterning covering up to 90% of its body. Horse may exhibit patches of color on the heads, knees, elbows, flanks (called "varnish marks"). Some may have as few as only one or two spots.

Snowflake - white spots, flecks, on a dark body. Typically the white spots increase in number and size as the horse ages.

Varnish - dark points (legs and head) and some spots or roaning over a light body. May occur in conjunction with another spotting style and change with age. Often starts out as a solid colored horse that gets more white as it ages, but is not a gray.

Frost - similar to varnish but the white hairs are limited to the back, loins, and neck. May occur in conjunction with another spotting style and change with age. Often starts out as a solid colored horse that gets more white as it ages.

The Appaloosa horse is currently one of America's most popular breeds. The majority of Appaloosas seen in horse shows today have an athletic build resembling the quarter horse and hunter type thoroughbred (heavy muscling is considered undesirable), however appaloosas come in a variety of body types including stock horses, sport horses, race horses and trail horses.

Young Appaloosa colt showing the characteristic, attractive white sclera of the eye, photo from Wikipedia - Creative Commons license

Horses are official state symbols in 10 states: Vermont and Massachusetts (morgan horse); Alabama (racking horse); Idaho (Apaloosa horse); Kentucky and Maryland (thoroughbred horse); Tennessee (Tennessee walking horse); North Dakota (Nokota horse); Missouri (fox trotting horse), and New Jersey ("the horse").