Five young sled dogs-in-training were recently born at the Denali National Park and Preserve in Alaska, as part of the park's sled dog breeding program.The Alaskan husky puppies are named Sequoia, Mammoth, Rainier, Teton and Mesa, after famous U.S. national parks, in a special nod to the upcoming 250th anniversary of U.S. independence. They will soon count a sixth puppy, Acadia, who will be joining the crew from another kennel.They are taking th…