Which Montana tributary was Emmet Sullivan born in?
Powder River (Wyoming and Montana) Powder River is a tributary of the Yellowstone River, approximately 375 mi long in northeastern Wyoming and southeastern Montana in the United States. It drains an area historically known as the Powder River Country on the high plains east of the Bighorn Mountains.
Boulder River (southwestern Montana) The Boulder River is a 77 mi tributary of the Jefferson River in southwestern Montana in the United States.