A. Missouri
B. Rio Grande
C. Colorado
D. Red River

Background of the Longest River in North America

The Missouri River originates in the Rocky Mountains of Montana, United States, and flows southeast before joining the Mississippi River near St. Louis, Missouri. Together, the Missouri and Mississippi rivers form one of the world’s largest drainage systems and have played a significant role in the economic, agricultural, and historical development of North America.

Historically, the Missouri River was an important transportation route for Native American civilizations and later became central to westward expansion in the United States. Today, it supports irrigation, hydroelectric power generation, flood control projects, and commercial navigation throughout several U.S. states.

Important Key Facts about the Missouri River

• Correct Answer: Missouri River.
• Length: Approximately 3,767 km (2,341 miles).
• Continent: North America.
• Source: Rocky Mountains, Montana, USA.
• Flows Into: Mississippi River.
• River System: Mississippi–Missouri River System.
• Economic Importance: Agriculture, navigation, irrigation, and hydroelectric power.

Exam Relevance: World Geography, Longest Rivers of the World, North American Geography, Missouri River, Mississippi River System, Physical Geography, CSS, PMS, FPSC, PPSC, NTS, OTS, FIA, MOD, ASF, ISSB, Lecturer Tests, and Competitive Examinations.