Complex sentence: The historical Pensacola people lived in part of a region that archaeologists call the Pensacola culture area, which extended along the coast of the Gulf of Mexico from Choctawhatchee Bay into what is now Louisiana.
Split into simpler sentences: The historical Pensacola people lived in part of a region that archaeologists call the Pensacola culture area. The Pensacola culture area extended along the coast of the Gulf of Mexico from Choctawhatchee Bay into what is now Louisiana.