• Photo: Paul Colangelo

    The sun rises over the boreal forest of Wood Buffalo National Park, Canada's largest national park, and among the largest in the world, that straddles the border of Alberta and Northwest Territories. (Photo: Paul Colangelo)

  • Photo: Paul Colangelo

    Bison gather on one of the few roads in Wood Buffalo National Park. The park was created in 1922 to protect the largest remaining herd of wild bison in the world. (Photo: Paul Colangelo)

  • Photo: Paul Colangelo

    An aerial view of the boreal forest of Wood Buffalo National Park affected by forest fire. Forest fires play an important role in the ecology of the boreal forest and are often allowed to burn naturally as long as they don't pose threats to assets within the park. (Photo: Paul Colangelo)

  • Photo: Paul Colangelo

    A forest charred by fire begins to regrow in a colourful display on the forest floor. (Photo: Paul Colangelo)

  • Photo: Paul Colangelo

    The mixed boreal forest of Wood Buffalo National Park. (Photo: Paul Colangelo)

  • Photo: Paul Colangelo

    One of the many sinkholes in Wood Buffalo National Park. Sinkholes are features of karst topology, where water-soluble elements such as gypsum, salt and limestone are dissolved to form sinkholes and caves. (Photo: Paul Colangelo)

  • Photo: Paul Colangelo

    Smoke rising from the boreal forest of Wood Buffalo National Park. Forest fires play an important role in the ecology of the boreal forest and are often allowed to burn naturally as long as they don't pose threats to assets within the park. (Photo: Paul Colangelo)

  • Photo: Paul Colangelo

    The aftermath of a forest fire in the boreal forest of Wood Buffalo National Park. Fires can get so intense that nothing but scorched ground remains. (Photo: Paul Colangelo)

  • Photo: Paul Colangelo

    Patterns of trees that have been reduced to ash spread across vast areas of Wood Buffalo National Park. Fire may be initially devastating, but it is the precursor of renewal. (Photo: Paul Colangelo)

  • Photo: Paul Colangelo

    The first signs of renewal after a forest fire occur near water. The renewal cycle starts with plants that thrive in the fire's aftermath. (Photo: Paul Colangelo)

  • Photo: Paul Colangelo

    Whooping crane nesting habitat in Wood Buffalo National Park. Wood Buffalo contains the only breeding habitat in the world for the whooping crane, an endangered species brought back from the brink of extinction through careful management of the small number of breeding pairs in the park. (Photo: Paul Colangelo)

  • Photo: Paul Colangelo

    Two whooping cranes in their nesting habitat in Wood Buffalo National Park. After spending winter along the Gulf Coast of Texas, whooping cranes return to these summer nesting ares. (Photo: Paul Colangelo)

  • Photo: Paul Colangelo

    A lone bison walking through the salt plains of Wood Buffalo National Park, which are unique in Canada. (Photo: Paul Colangelo)

  • Photo: Paul Colangelo

    An aerial view of the salt plains of Wood Buffalo National Park, which are unique in Canada. (Photo: Paul Colangelo)

  • Photo: Paul Colangelo

    An aerial view of the salt plains of Wood Buffalo National Park, which are unique in Canada. (Photo: Paul Colangelo)

  • Photo: Paul Colangelo

    A herd of bison moving through the Peace-Athabasca delta. (Photo: Paul Colangelo)

  • Photo: Paul Colangelo

    The mixed boreal forest and grasslands in Wood Buffalo National Park. Wood Buffalo National Park is the most ecologically complete and largest example of the entire Great Plains-Boreal Grassland ecosystem of North America. (Photo: Paul Colangelo)

  • Photo: Paul Colangelo

    A river meander in Wood Buffalo National Park. Dramatic meanders are a common scene in the Peace-Athabasca Delta, where it's flat landscape fails to plot an obvious course for the waterways. (Photo: Paul Colangelo)

  • Photo: Paul Colangelo

    Trees follow the meandering path of a river in the Peace-Athabasca Delta. (Photo: Paul Colangelo)

  • Photo: Paul Colangelo

    The still surface of the Peace River reflects the smokey sky. Due to the flat land, the rivers' currents are so low that canoeing upriver often isn't a challenge. (Photo: Paul Colangelo)

  • Photo: Paul Colangelo

    An aerial view of sand patterns in the Peace River in Wood Buffalo National Park's Peace-Athabasca Delta. (Photo: Paul Colangelo)

  • A braided river emptying into the Peace-Athabasca delta in Wood Buffalo National Park, which is the world's largest inland river delta. (Photo: Paul Colangelo)

The challenge of photographing Canada's largest national park — and one of the largest in the world — is simply covering all the ground. The only possible way was from the air, hovering above the landscape on a six-hour helicopter flight.

And from the air, you get a sense of how this landscape works. What one would expect to have been a vast tract of homogenous boreal forest is forced into flux by two agents of change: fire and water.

Every direction you turn, smoke is rising from the forest. Park staff members protect cabins and critical infrastructure, but otherwise let fires burn, as they are an important part of the ecosystem. The land is burned into a patchwork of the full spectrum of stages of boreal growth, from charred moonscapes to lush first-growth to mature woods.

Rivers flowing into the Peace-Athabasca Delta, the largest inland river delta in the world, wind their way from every corner of the park. The flat landscape fails to chart an obvious course, so the rivers indulge in wide, dramatic meanders before cutting themselves off to form oxbow lakes, which in turn dry out and scar the landscape. These rivers without gravity are constantly altering the landscape and are so slow you can paddle upriver effortlessly — a paddler's dream but a cartographer's nightmare.

From the air, you can watch fire and water transform Wood Buffalo National Park into a unique landscape and wildlife refuge.