50 Life Along the Colorado-Mid

Life Along the Colorado FOCUS Question How does the environment change along the Colorado River?

The Mighty Colorado The southwestern United States is a dry and thirsty place. But a mighty river flows through it, bringing moisture and life to a parched land. This river is the Colorado. The Colorado River is over 2,200 kilometers (1,400 mi.) long The river begins high up in the Rocky Mountains at 3,000 meters (10,000 ft.) and flows all the way to the Gulf of California. Along the way, the river passes through a wide range of environments. Many types of plants and animals call these places home.

The River's Many Regions The Colorado flows through four main regions on its way to the ocean. The regions have different air and water temperatures. Where the river begins, temperatures are cool all year. Winters are long, cold, and snowy. In the lowest regions, temperatures can reach over 38°C 100°F for several months each year. The river itself is also different in these regions. In the mountains, small, fast-flowing streams feed the Colorado. The river is large and swift in the canyons. In the lowlands, it is slower but still large. The last region has broad, shallow waters with very little flow.

In the Zone Along the entire length of the Colorado River is a riparian zone. This term describes the land on both sides of a stream or river. These zones are important to the health of habitats along rivers. They are sometimes referred to as "ribbons of life." The flowing water carries sediments and nutrients. which make the soil rich Because of the water and rich soil. these areas often support more plants than the surrounding areas. The plants attract many types of animals. Many of these plants and animals can only survive in the riparian zone.

Mountains The Colorado River begins as several small streams high in the Rocky Mountains. Most of the water comes from snowmelt in late spring. The small streams join together as they flow down through forests. By the time the water reaches the next region, the Colorado is a large river. The highest areas of this region have an alpine habitat. Strong, freezing winds force many small trees to grow low to the ground. Some animals have heavy fur or feathers for protection from the cold. Some mammals hibernate in burrows. Many birds migrate to warmer places during winter.

Canyons In the second region, the now-large Colorado River carves its way through deep, rocky canyons. Some areas are up to a mile deep as the river flows through the Grand Canyon. The river once carried large amounts of silt and sand as it rushed through the canyon. Yearly floods allowed sandbars to form and washed away plants on the banks. Shrubs and trees grew on higher slopes, above the flood level. Now, large dams control the water flow through the Grand Canyon. This keeps silt and sand from freely flowing along the river. Fewer sandbars and clearer, colder water make it hard for native fish to survive.