The Northern Boreal Mountains ecoprovince covers the northwest corner of the province. It is the territory of the Tutchone, Tagish, Inland Tlingít, Kaska, Dena, and Tahltan First Nations.
The region gets some rain in summer and some snow in winter. Its winters are longer and colder than the rest of the province. Summers are short, cool and dry. The climate is similar to parts of the Yukon and the Arctic.
There are many birds that breed only in the Northern Boreal Mountains ecoprovince such as the Arctic Tern and the Snow Bunting.
The major cities are Atlin, Cassiar and Telegraph Creek.