Models of paleolithic settlement and site discovery in rift valleys are offered both to explain the settlement geography and to predict the location of additional sites. These models are scaled to the perspectives of region, landscape, and local resources. Paleoterrains associated with stratified assemblages of paleolithic artifacts along the upper Semliki River, Western Rift, are described. Increasing degrees of environmental awareness, as signaled by increasing sophistication in selection of site locations, are fundamental to measuring progress in the human career. Oldowan occupation was on sandy substrates on the central floor of a wide stream channel, while Acheulian occupation, fragmentary in this region, is associated with a channel margin setting. Middle Stone Age settlement, as recorded at the important locality of Katanda, indicates more sophisticated selection of terrains in order to exploit several kinds of resources along the river valley. Settlement pattern during the Late Stone Age was essentially modern, emphasizing locations where both riparian and upland resources could be readily exploited. The meanings of site locations in paleolithic archaeology are much more than just the geography of modern discoveries.