Columbia subject headings:
Harvard subject headings:
Botany--Northwest Territories--Mackenzie River Valley.
Botany--Yukon Territory.
Paleobotany--Northwest Territories--Mackenzie River Valley.
Paleobotany--Yukon Territory.
Princeton subject headings:
Botany--Northwest Territories--Mackenzie River.
Botany--Yukon Territory.
Paleobotany--Northwest Territories--Mackenzie River.
Paleobotany--Quaternary.
Paleobotany--Yukon Territory.