Alaska’s known as “the last frontier,” a phrase that conjures an image of a bygone era of untouched expanses and wide-eyed exploration of a land frozen in time.

The moniker couldn’t be more fitting. For within Alaska’s boundaries is some six-million acres of almost entirely untouched, painstakingly preserved terrain: Denali National Park.

Set aside by the federal government as a protected wilderness area in 1917, today Denali is the most popular tourist destination in Alaska. It is a place of inconceivable diversity. Winter is nine months long, yet the area is considered a subarctic desert. The ground is covered in extremely rare plants which grow only in earth that never completely thaws. Majestic mountains—including Mt. McKinley, the continent’s tallest—are covered in glaciers. And throughout every corner of the park is abundant wildlife ranging from grizzly bears to sheep. All this flora, fauna and terrain combines in one of the world’s few (some say the only) examples of an unaltered subarctic ecosystem.

So how does a park so rare and popular keep so pristine? Cars are all but banned, substituted instead with a fleet of guided tour buses. There is virtually no pavement either—just gravel. Teams of scientists monitor everything from the introduction of  non-native plant species on the soles of visitors’ shoes to air quality. And all the diligence has certainly paid off. Denali has Alaska’s highest-quality air, making Mt. McKinley, the star attraction of Denali, visible on a clear day from as far as Anchorage, some 130 miles away.

All the painstaking preservation has not made Denali the look-but-don’t-touch place you might imagine. There is river rafting of the serene and heart-palpitating variety on a number of incredibly gorgeous waterways. There are camping areas so remote and quiet you would swear you were the only people around for miles. There is wildlife everywhere you turn—bears, elk, moose, sheep, fox, wolves, caribou, not to mention the husky kennel where Iditarod champion Jeff King raises his prized canines. You can hop on a helicopter and be dropped off on the nearest glacier. Or, you can hike. And hike. And hike. Most of the park has a trailless hiking system, which means the route you take is the one along which your curiosity leads. And what better way can there be to experience this precious land than meandering along with Mt. McKinley’s peak to guide you?