I cannot see the map you're referring to. However, I can provide some general information:
- The Southeast Plains typically refer to areas in the southeastern United States, characterized by flat terrain and low elevation.
- The Great Plains are a vast area in the central United States known for their flatlands and agricultural suitability, extending from Canada to Texas.
- The Rocky Mountains are a major mountain range in western North America, characterized by steep, rugged terrain and high elevations.
- The Coastal Plains would refer to flat, low-lying areas near coastlines.
If you could provide a description of the shaded area or more context, I could help you identify it more accurately!