Ethnoarchaeological research has shown that the assumptions formerly guiding the investigation of hunter-gatherer site structure are invalid, at least as general rules. Further research is now required to identify the determinants of site structure and assess their effect. Here I describe those aspects of Alyawara behavior that shape site structure at residential base camps. I then compare certain features of the Alyawara case with those of the !Kung and the Nunamiut. I tentatively infer that most of the variability in site structure in these cases is a function of differences in the degree of reliance on food storage, seasonal variation in weather, household population size, and the length of time activity areas are in use. Predator pressure and the relative importance of interhousehold food sharing may also be involved. The apparent importance of food storage suggests that variation in site structure may parallel Binford's (1980) forager-collector continuum. Further research is required to determine if this is so, and whether other aspects of behavior also affect site structure. These observations have important implications for the conduct of archaeological research, especially for the spatial scales at which analyses of site structure are undertaken, and for the sizes of refuse items considered in such analyses.