The spiritual side of the prehistoric people of Iowa was an important part of their daily lives. And they left evidence of this on the Iowa landscape in their burial mounds. Beneath these mounds they buried their dead. Sometimes in hollowed out log tombs, which were burned and then covered with dirt. But not all mounds served as burial refuges for the dead. Many have been found to contain only elaborate artifacts, such as carved stone effigy pipes and items from distance lands: ceremonial breast plates made of copper from the shores of Lake Superior, shells form the Gulf of Mexico, articles made of a hard volcanic rock know as obsidian from the Rocky Mountains and mica from the Appalachian Mountains. But how did these objects from such different places get into the possession of the Indians of Iowa? Archaeologists believe that the mound builders must have been part of an elaborate trade network with tribes across the continent. Some of these objects considered sacred to the Indians were passed along by distance tribes until eventually they were traded to people living in Iowa. Since such items were not native to this area, they were treasured by the mound builders. The mound builders felt a close kinship to all of nature which surrounded them. All the creatures of the earth were their brothers: the bears in the forest, the birds in the air. All had great meaning to these people. During times of plenty when there would be a great abundance of wild plants available, such as the fall of the year, many different groups would get together to exchange trade items, tell stories and reestablish territorial boundaries. With the surplus of manpower available they would build mounds in animal shapes, or effigies. Did the shape of the bird or bear mound have some sacred meaning to these people? Perhaps they were paying homage to whose spirit guided their group. Why was this site, over looking the Mississippi River, chosen? Could the mounds have been territorial boundaries between groups of Indians? Although there is much that we do know about the people from prehistoric Iowa, there is still much that we do not know and many questions will remain unanswered forever.