The Tatshenshini-Alsek Park links the three adjacent national parks, Kluane in the Yukon and Glacier Bay and Wrangell- St Elias in Alaska, to create a 97 000 square kilometre ecological unit and bi-national World Heritage Site. Situated in the extremely rugged northwest corner of British Columbia, in 1993 it became the fourth component in the largest international protected area in the world. Half the landscape is permanently covered in snow and ice - the other half fosters forests and tundra and stable populations of wildlife untouched but for a historic aboriginal presence. To ensure the preservation of the entire ecosystem, the Tatshenshini and its tributary, the Alsek, are completely protected from headwater to source - the only large river drainage in North America that is completely safeguarded.