What is the most important river in North America? The Mississippi River is the most significant due to its role in trade, transportation, and agriculture, spanning 2,340 miles (3,766 km). 3.

North America is the third largest continent in the world ... which lasted from 1968 until 2010 - more than 40 years. The Missouri River is the longest river in North America.

- The Lewis and Clark expedition followed this route. - Largest river by drainage area. - Watershed: 1.2 million sq miles. - Flows through 10 states. - Flows through Alaska. - Watershed: 328,000 ...