More than a thousand years ago in this area, people built their homes, raised their families, made tools, and prepared meals, creating a midden, or built-up area, from the bits and pieces of their everyday lives. The mounds and midden here are made up mostly of oyster shell, showing that oyster was a major food source and building material for the people who lived in Crystal River. They also relied on hundreds of different species of plants, fish, reptiles, and mammals for their meals.