Its eastern boundary is located by
Great Bear and
Great Slave lakes in the
Taiga Shield, site of the world's oldest known rock formations. To its south are the
Boreal Plains, a vast forest of
spruce and other
timber with numerous
wetland habitats. Portions of Wood Buffalo National Park and
Whooping Crane Summer Range, the only nesting area for the critically endangered
whooping crane, overlap onto the Taiga Plains from the Boreal Plains. To the west it abuts the foothills of the
Boreal Cordillera in British Columbia and southern Yukon, and the
Taiga Cordillera further north. These two ecozones comprise the
Mackenzie Mountains. Its northern borders are with the
Southern Arctic ecozone in northeastern Northwest Territories, and the
Arctic Archipelago Marine ecozone at the delta of Canada's largest river, the
Mackenzie. The ecozone consists primarily of
strata of
limestone,
shale, and
sandstone sedimentary rocks, The western portion, dominated by the Mackenzie, is more rugged with deep canyons and trenches cut by the river and tributaries.
Ecoprovinces This ecozone can be further subdivided into three ecoprovinces: •
Great Bear Lowlands •
Hay-Slave Lowlands •
Mackenzie Foothills ==Climate==