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Why Is the Missouri River So Brown?

Why Is the Missouri River So Brown?

Over 250,000 rivers in the United States stretch for a staggering 3.5 million miles. The Missouri River is the longest. At 2,341 miles long, it’s 200 miles longer than the Mighty Mississippi River. It’s also the 15th longest river in the world.

However, the Missouri River’s color is another unique characteristic of this lengthy river. So why is the Missouri River so brown?

Let’s see.

Where Is the Missouri River?

The Missouri River begins just west of Bozeman, Mont. Three rivers merge, and the result is the Missouri River. It flows east out of Montana into North Dakota, passing through Bismarck on its way through the middle of South Dakota. 

From South Dakota, it travels down to make up the eastern border of Nebraska and the border between a portion of Kansas and Missouri. The river then continues eastward across Missouri before reaching St. Louis, where it empties into the Mississippi River and eventually the Gulf of Mexico.

The Missouri River at sunset
The Missouri River was crucial for westward expansion in the US.

Why Is the Missouri River Famous?

The Missouri River has had a very important job throughout its life. The river has been a tremendous resource for food, irrigation, and water. It played a huge role in the country’s westward expansion as settlers headed west.

In 1804, famous explorers Lewis and Clark became the first to travel all 2,341 miles of the river. There is a Lewis and Clark historic trail where travelers can follow the Missouri River and enjoy approximately 100 different historical sites related to the explorers.

Another factor that makes the river very well known is that some of the most popular national parks are a part of its watershed. These parks include Glacier National Park, Yellowstone National Park, Badlands National Park, and Rocky Mountain National Park.

Pro Tip: Learn more about the history behind Yellowstone National Park.

Two people kayaking down Missouri River
The Missouri River is very muddy making it a brown color.

What 3 Rivers Make Up the Missouri River?

Just west of Bozeman, the Gallatin, Jefferson, and Madison rivers merge to form the Missouri River. From there, the waters travel 2,341 miles until they meet up with the Mississippi River in St. Louis, Mo. The waters then travel an additional 1,278 miles before dumping into the Gulf of Mexico in New Orleans, La. 

Why Is the Missouri River So Brown?

The Missouri River has the nickname “The Big Muddy.” The river earns this nickname as it carries a tremendous amount of dirt and sediments from the western and mid-western landscapes. Large amounts of rainfall cause runoff waters from the surrounding landscapes and river banks to flow into the water. 

Erosion and flooding fill the Missouri River with a large amount of dirt, which gives it a brown color. Despite its less than charming color, the river is relatively clean. However, like many large rivers, toxins from farming and industrial plants find their way into the river.

What Does It Mean if River Water Is Brown?

Rivers and other water systems with a deep brown color are typically due to large amounts of sediment and silt. Depending on the levels of rain in an area, the soil and dirt from the river banks and surrounding fields can run off into the water.

Dumping large amounts of soil and dirt into the water is enough to change its color. It’s like making a pitcher of Kool-Aid or your favorite powdered drink mixture.

The result is the color of water changing based on the weather. Expect to see deeper brown colors after heavy rains. The color change often provides researchers with clues as to the health of the river’s ecosystem. 

Pro Tip: Spend the night at one of these 6 Best Free Camping Spots In Missouri.

View over the Missouri River
While the Missouri River is brown in color, it is not the dirtiest river in the US.

Is the Missouri River Always Muddy?

The Missouri River always has a brown tint to it. However, depending on the weather conditions along the river, the intensity of the muddiness can vary quite a bit. The river is typically muddier during the spring as snow melts at higher elevations, and lower elevations experience rainy seasons.

This causes water levels to rise and wash away any loose soils and sediment along the river.

What Is the Dirtiest River in the US?

While the Missouri River may appear dirty because of its deep brown color, that’s not necessarily the case. However, the most polluted river in the United States is the River Rouge.

The river contains more than 200 pollutants, including zinc and lead. Many of the fish living in the River Rouge show signs of dangerously high mercury levels. It’s safe to say you’ll want to practice catch and release with any fish you catch in this river.

Is the Missouri River Worth Visiting?

The Missouri River is a unique part of American history and worth experiencing. Its massive length makes it easy for travelers to experience the river in many locations throughout the country. If your travels take you across the Great Plains or north of St. Louis, you’ll have a hard time not crossing it.

Visiting some of the Lewis and Clark historical sites can be a great way to learn about the area’s history and what the explorers would have encountered on the river.

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