Three of the newborn sled dog puppies at Denali National Park and Preserve in Alaska. Mammoth (left), Sequoia (center), and Rainer (right) | Image credit: Denali National Park and Preserve/NPS The puppy cam at Denali National Park and Preserve in Alaska went live this week, giving the public a chance to watch these famed sled dogs as they grow up to become future canine rangers. Sled dog teams at Denali National Park date back to 1922 and have been an integral part of the park’s landscape for over a century. Sled dogs at the Alaska park are working rangers, helping scientists and staff by providing transport in harsh winter conditions, monitoring conditions, helping establish winter routes, and carrying heavy supplies where motorized vehicles aren’t allowed. Puppies Mesa (left) and Teton (right) | Image credit: Denali National Park and Preserve/NPS Denali National Park’s latest litter of sled dogs — Sequoia, Mammoth, Rainier, Teton, and Mesa — were born on March 30.…