The last major cultural tradition in prehistoric North America, the core area of which was the central Mississippi Valley. At its maximum extent it covered most of the southeastern USA and had outposts as far north as Aztalan in Wisconsin. Although there is considerable internal variability, its characteristic traits are the platform mound (frequently built on large open plazas), intensive valley-bottom agriculture, and distinctive shell-tempered pottery. Hunting and gathering persisted as a means of subsistence throughout, but typically sites are located close to rivers on good agricultural land, with the flint hoe being the most common artefact. Defensive works (seeCAHOKiA, Etowah) are also a common feature. Architectural, agricultural and ceremonial traits (see Southern Cult) display undeniable similarities to those of contemporary Mesoamerica, but the true dynamics of this relationship are still unclear. Mississippian characteristics began to appear in c700 and its cultural climax and maximum geographic extent date to 1 ZOOKOO (seeTable 9, page 552). By the late 17th century, all the major centres had been abandoned. See also Temple Mound Period.