Samples of bone and soil collected in 1958 show highest values for Sr 90 in the tropical region on the east side of the Andes. Lowest values are found in the high central valley, where samples used in estimating world-wide distribution of fallout were collected. If the major fallout deposition occurs in the interior of the South American continent, such estimates for these latitudes may be low by as much as a factor of ten. Although there has apparently been greater Sr 90 deposition in regions of greater rainfall, analysis of data from 16 locations fails to show a significant correlation between rainfall and fallout.