The park is located in the very northwestern corner of British Columbia, bordering the American state of Alaska and the Canadian Yukon Territory.

Over the centuries, numerous indigenous peoples lived in this area, including the historic Tlingit and Southern Tutchone, who built fishing villages along the rivers.

In the mid-1970s two companies began rafting the Tatshenshini (aka "the Tat", a term also used to refer to the region) and Alsek rivers for the first time.

An extremely intensive campaign followed in Canada and in the United States, particularly the U.S. Congress and eventually the White House, when the active involvement of then Vice-President Al Gore was enlisted.

Eventually, BC Premier Mike Harcourt responded by undertaking a review of the issues surrounding Tatshenshini-Alsek by the Commission on Resources and the Environment (CORE).

The International Union for the Conservation of Nature (IUCN) proposed the area for protection as a UNESCO World Heritage Site.

Some 241 volunteers were tested from the area Champagne and Aishihik First Nations, and related peoples in Yukon, British Columbia and Alaska.

A green area that cuts through a barrier of mountain and ice connects coastal and interior grizzly bear populations and provides valuable habitat.

This extremely rare blue-grey colour phase of the black bear is found only within the park and just over the border into the United States.

As well as bears, Tatshenshini-Alsek Park also supports Dall's sheep, and exceptional numbers of mountain goats, Kenai moose, grey wolves, eagles (bald and golden), falcons (peregrine and gyr), and trumpeter swans.