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distribution of nonscoocd samples collected for control purposes. The central Utah samples. collected at approximately two-week intervals. also providoo no cvidence that seeding was enhancing silver concentrations in the high-altitude snowfalls. In contrast. the randomized Bridger Range Experimcnt (BRE) conductt.-d in southwestern \1ontana is presented as an examplc of how trace analysis of silver-in-snow can offer evidencc of pos."ible targeting success in support of statistical suggestions and othcr physical obscrvutions" The BRE. discussed by Super and Ileimbach (1983). di1Tcn..~ from previously discusscd investigations in that only high alLitudc Agl generators \\ere used. They \\cre sited about 2/3 of the wa)" up the windward barrier slope. only 1500 ft below thc a....cragc crest line elevation. Considcrable evidence ha." been published sho\\ lng thesc high altitude rdc-dSCS resulted in routine T &0 of the AgI over the target area. Such frequent targeting has not been demonstrated in other winter oro~>raphic St..\-.>ding programs. which used ground-based generators. Sca<;(mal samples \\cre obtained from snow piL" dug during March (prior to any snol,>,mdl) of the linal two BRE randomized seeding seasons. These samples were from 7 different sites spaced o....er the expectcd target area. Silvcr levels analyzed by DRI showt.~ that thc natura) snow was below the detection limit of about 10,11 gram per milliliter by wcighL equivalent tolO ppl while seedl.-d samples ranged from 30-100 ppt. The median of 14 seasonal target samples was 46 ppt. Presumably silver contents would havc been twice as great. in the 60- 200 ppt rangc. "";th mt.-dian near 90 ppt. had St..'t..~ing not been randomized with about half of all storms Icft unseeded. About 40-70 percent of the total silver emitted during hours of target snowfall was estimated to he in the seasonal target snowpack above 6.000 ft. Tht..'S!: lrace chemistry findings were in a~rreemcnt with other physical and statistical resulLS reported by Super and Heimbach (I QS3). ain.:rdfi microphysical measun'ments discussed by Supcr and Heimbach (1988). and C"drlicr aircraft T &D observations of Agl presented by Super (1974). Had targct silver Icvels not been signilicantly cnhanced. the strong statistical suggestions of ~-eding success would ha\'c to be rejt.."Cted as contrary to physical e...idcnc~. An operational Sl.'\.-ding program with "pigg)"backcd research" was conducted on thc Bridgcr Range for a single v.inter. One of the prior experimcnLal Agl generator sites was US4.>d. just upwind of the intendt.-d target. the Rridger Bowl Ski Area on Ice slope of thc main ridgc. The ski area was ccntcred only 2.5 miles (all statutc miles) from the Agl gencrator. located well up the windward slope: of thc main ridgc. A line of 7 snow pits was dug soon aftcr seeding terminated. to provide seasonal samples perpendicular to the prevailing transport winds aloft. They wcre again analyzed for sil....er content by DRI as reported by Heimbach and Super (1988). A marked north-south gradient resulted. v.ith siher le....els below the detection limit of about 10 ppt on the north and south ends ofthc line. crosswind ofthc expected target. Valucs v..ithin the ski area target wcre between 20-90 ppt \\>ith only one sample below 40 ppt. A single sample was taken several miles farther downv.;nd near the cenlcr of the previous BRE target area. It yielded about 50 ppt. and was likely targeted onl)" part of the timc by Lhe single Agl generator. The above l'\.."'Sults demonstrate the importance of using silver.in.sno\\ anaIvsis to It.-st anv projt.'"Ct St.."\.-ded v.ith AgI. since poor targeting has been shown for some long-tenn' projects. e\'~ when using rcmotC'-(;ontrollcd AgI generators abO\ C' \ alley tloors. 11