Activity in excess of 200,000 d/n/ft* on sampling day occurred at two stations in the United States following the Yankee burst (Billings, Mont., and Salt Lake City, Utah) and was a result of dry fallout at Salt Lake City and with rain at Billings. These values exceed by an order of magnitude the maximum fallout revorted at any of the Japanese stations and are larger than the maximum values reported at many of the Pacific Islands much closer to the Pacific Proving Ground. (It should be noted that it is likely that Kusaie, Ponape and Kwajalein received their maximum activity following the Bravo burst, however, these stations did not start gummed film observations until about two weeks after this burst and the values given probably do not represent the maximum fallout for the Castle series.) - 35 =