Leonard Seppala was one of the earliest kennels working with the dogs that were being imported directly from Siberia. In the early 1900's sled dog racing was becoming more popular and the "Little Siberian rats" ruled the races from the moment they first landed. At that time many people described them as being almost  "foxy", or even "wolfy, but much smaller". They were usually 50 lbs or less, with thick warm fur, small prick ears, sickle tails, the innate desire to run, and the ability to pull moderate loads over long distances. These speedy dogs could cover a great deal of territory efficiently, with out tiring, and eating almost nothing. They were significantly faster than the heavy freight style crossbreds that were being used at that time. During the Diphtheria epidemic in Nome, Leonard, led by Togo and Scotty,  ran the longest leg of the relay (the total distance covered being approximately 360 total miles including going out to the rondezvous point etc) that brought the serum to the stricken town. From all of the many dogs and teams that ran, one lead dog, Balto, took a superhero's place in the newspapers and entered into the history books. Balto of Seppala's true story is that he was a dog Leonard considered to be of lesser quality and the dog was sent to run for another musherGunnar Kassen hauling freight for the mining company that employed the two men.. Balto ran lead for part of the last, and shortest leg (50 miles), through horrible weather,  and into main street Nome. Kassen and Balto became heroes, but with the growth in popularity of dogsled racing Leonard Seppala's Siberian Huskies became world famous.
 
 

Leonard Seppala's dog famed Balto, the leader of the last team in the relay that brought the Diphtheria serum to Nome

Kassen, Balto and the team toured the US for a few years, the team finally retiring on public display at a zoo. Leonard took his dogs and began racing in the lower states and with Togo he toured the US. Eventually Seppala finally returned to his Alaska and beloved dogs and continued on sledding and breeding the best racing huskies of their time.  Eventually Leonard's dogs were found in many kennels, but it was inHarry Wheeler's "Of Seppala" kennels in St. Jovite Station, Quebec, that the line progressed in possibly it's purest form. The "Seppala" as a pure line was maintained in Canadian  (primarily in "of Seppala", Markovo, and Seppineau kennels) though to the 1960's with a small pocket of dogs from Seppala also being located in Poland Springs (USA).

Many breeders today proudly trace their lines to Seppala bloodlines. It is very common to see "Sepp" as part of their kennel names. This claim to have pure, or even strong, "Seppala bloodlines" is not always truly accurate. In the 1990's a movement grew in Canada's Yukon to "locate and rescue" the pure Seppala bloodline from the remaining Canadian dogs. A registry for the "Seppala Sleddog Project" was developed to help identify and preserve the historic genome.

The modern Seppala racing sled dog is highly valued for its ability to speed race. Touring, sprint, mid-distance, long-distance and recreational sledding are all strongholds of the Seppala. Regardless of what fraction the observer, or owner, is from, the ability and athleticism of these dynamic dogs is unmistakable.