Geologic Unit: Telegraph Creek

Usage:

Telegraph Creek Beds of Gammon Member of Cody Shale (northwestern Powder River basin of MT*,WY*)
Telegraph Creek Member of Cody Shale (MT*,WY)
Telegraph Creek Member of Colorado Shale (MT)
Telegraph Creek Formation (MT*)
Telegraph Creek Formation of Montana Group (MT*)

Subunits:

(alphabetical): Elk Basin Sandstone Member (MT*,WY*).

Geologic age:

Late Cretaceous (Santonian to Campanian)*

Type section, locality, area and/or origin of name:

Typically developed at head of Telegraph Creek, in T. 2 S., R. 28 and 29 E., Crow Indian Reservation, Yellowstone Co., central southern MT (Thom, 1923).

AAPG geologic province:

Central Montana uplift*
Montana folded belt*
Sweetgrass arch*
Williston basin*