Even the Indians have made use of this symbol. On Big Medicine Butte, in Dakota Territory, near Pierre, is a train of stones arranged in the form of a serpent, which is probably the work of the Sioux Indians. Around about on the hill is the burying-ground of their chiefs. This was to them sacred ground, and no whites were allowed near. The stones are about the size of a man’s head, and are laid in two rows, from one to six feet apart. The length in all is three hundred and fifty feet, and at the tail, stones, to represent rattles, are rudely carved. The eyes are formed by two big red bowlders. No grass was allowed to grow between the two rows of stone.55
It seems reasonable to suppose that the few isolated effigy mounds we have outside of Wisconsin were built to subserve a different purpose than those in that State. Mr. Peet has made some remarks on their probable use that seem to us to cover the ground, and to do away with any necessity of supposing on the part of its builders an acquaintance with Old World mythologies. Nature worship is one of the earliest forms of worship. The prominent features of a landscape would be regarded as objects of worship. Thus, for example, the island of Mackinac resembles in its outline the shape of a turtle; so the island was regarded as sacred to the turtle, and offerings were made to it. A bluff on the same island at a distance resembles a rabbit; accordingly, it was called by that name, and offerings were made to it. It is quite natural that the effigy-mound builders should seek to perpetuate by effigy some of these early traditions.
In the case of the Big Serpent mound this point is worth considering. The ridge on which it stands is not only in the midst of a wild, rough region, but is so situated that it commands a wide extent of country. In shape this tongue of land is also peculiar. It is a narrow, projecting headland, and would easily suggest the idea of a serpent or a lizard. “This, with the inaccessibility of the spot, would produce a peculiar feeling of awe, as if it were a great Manitou which resided there; and so a sentiment of wonder and worship would gather around the locality. This would naturally give rise to a tradition, or would lead the people to revive some familiar tradition and localize it.”56 The final step would be to make an effigy.