Final answer:
The land on a westward journey from the Mississippi River to the Pacific coast gradually increases in height, from the Mississippi River to the Rocky Mountains and the coastal ranges.
Step-by-step explanation:
The land on a westward journey from the Mississippi River to the Pacific coast in terms of elevation can be described as gradually increasing in height. Starting from the Mississippi River, which has a lower elevation, as you move westward, you will encounter the Great Plains, which are relatively flat. Then, you will encounter the Rocky Mountains, which are a major mountain range in North America and have higher elevations. Finally, as you approach the Pacific coast, you will encounter the coastal ranges, which consist of lower mountains and valleys.