from the Area 11 sites at NTS and the Roller Coaster sites at the Tonopah Test Range (TTR) have undergone radiochemical analysis. Listed below are some pertinent findings: 1. Th e 239-240 Pu and 241 Am contamination levels varied from sample to sample collected within a given activity stratum defined by FIDLER survey instrument. These variations were of an order of magnitude attributable to differences in the amounts of resuspendable particulate material superficially entrapped upon plant foliage. The results also indicate that the activity levels found on vegetation may be attributed largely to superficial contamination in these aged fallout areas. 2. Reasonable agreement occurred between the mean activity levels of plutonium in vegetation and soil samples collected across different activity strata within each fallout area. The ratio of vegetation Pu to soil Pu tended to increase moving out from higher to lower activity strata. 3. Results indicate a reasonably constant Pu/Am ratio for vegetation samples collected from a given fallout area. This ratio, however, varied among the separate test events as the result of differ- ences in the ingrowth of 241 am within the aged fallout source materials. 4, The Pu/Am ratios were strikingly lower in vegetation samples than in soil samples from the Roller Coaster sites. A less pronounced trend was found in three of six activity strata sampled in Area 13 and at the Area 11 C and D sites. The reverse relationship (i.e., slightly higher ratios in vegetation than in soil samples) occurred at GMX-5 and Area 11 8B. The real signifi- cance of these trends is not yet understood; however, the GMX-5 site had 22 test events, while the other sites each had a single event. One possible explanation for the Roller Coaster sites is that one of the more biologically available ingrowth products, 241an, has moved deeper into the root zone where greater root 239-240 uptake has occurred relative to Pu. Results from soil profile samples should indicate how much movement has occurred. 32