Columbia subject headings:
Geology, Stratigraphic--Proterozoic.
Geology, Structural--Montana.
Prospecting--Montana--Geophysical methods.
Thrust faults (Geology)--Montana.
Harvard subject headings:
Geology, Stratigraphic--Proterozoic
Geology, Structural--Montana.
Prospecting--Montana--Geophysical methods.
Thrust faults (Geology)--Montana.
Princeton subject headings: