d) Red River

The Red River creates natural borders for Texas, Louisiana, Arkansas, and Oklahoma. This major river in the southern United States is known for its reddish-brown waters, caused by eroding red soils along its watershed. The Red River is a significant geographical feature in the region, playing an important role in agriculture and providing vital water resources for the states it borders. The river’s basin supports a diverse ecosystem and is a key habitat for many species of fish and wildlife.