The Negro River is one of the largest tributaries of the Amazon River in South America. It flows through Brazil and Colombia, covering a distance of approximately 2,250 kilometers (1,400 miles). The river is known for its dark-colored water, which is caused by the decomposition of organic matter in the surrounding rainforest. The Negro River is an important waterway for transportation and supports diverse ecosystems along its banks. It is home to various species of fish, birds, and other wildlife, making it a vital habitat in the Amazon Rainforest. The river also plays a significant role in the local economy and culture of the communities that live nearby.