Hopewell sites are characterized by "gigantic earthworks" (458)
"A typical Hopewell site is a complex, mathematically aligned mix of circles, squares, and octagons -- all made of mud."
see "the Newark Earthworks in [what is now] Licking County"
prior to the development of the Hopewell Interaction Sphere, "geometric earthworks across large parts of the Americas appear to have been using the same system of measurement: one apparently based on the arrangement of cords into equilateral triangles"
"the geometric systems characteristic of the 'Woodland peoples' who creared Hopewell," however, "mark something of a break with past custom: the introduction of a different metrical system, and a new geometry of forms"
"Sites with earthworks based on this new, Hopewellian geometrical system can be found dotted along the upper and lower reaches of the Mississippi valley. Some are the size of small towns"
"for most of the year these sites remained largely or completely empty"