A river that flows for 625 miles (1,000 km) through northwestern Montana and southern Alberta, into the Missouri River. It is the most northwestern part of the Missouri-Mississippi river system.
Definition of Milk River in US English:
Milk River
proper noun
A river that flows for 625 miles (1,000 km) through northwestern Montana and southern Alberta, into the Missouri River. It is the most northwestern part of the Missouri-Mississippi river system.