Southeastern United States Spot measurements constitute the major portion of the data obtained in the southeastern United States enroute to and from Houston, Texas. The measurements in Houston and Galveston were made in conjunction with the International Symposium on the Natural Radiation Environment at Rice University and are dis- cussed in an appendix to the Proceédings.® On the return trip to New York, several measurements were made in the area of Aiken and Lexington, South Carolina. These measurements were made as a cooperative venture with the Aerial Radiological Measuring Surveys group (ARMS)° and were of interest in that fairly large variations in natural levels were found in a rel- atively small area. These variations were due primarily to varying Th232 soil concentrations. This area also was notable in that potassium soil concentrations appeared to be quite low. High Th232 dose rate contributions were also obtained at loca- tions in the Raleigh, North Carolina vicinity. Fallout levels during this trip were found to be relatively high, mostly ranging between 4 and 5 ur/hr. Central and Western United States In October of 1962 an extended survey trip was undertaken between New York City and the west coast, concentrating on the following areas: (1) Sundance, Wyoming and vicinity, (2) the Olympic Peninsula in Washington, (3) the San Francisco Bay area, and (4) Denver and Colorado Springs, Colorado. A part of this survey was repeated in October 1963 in order to recheck several measurements and also to obtain additional measurements in the Denver area, Sundance, Wyoming and Vicinity The Sundance area measurements were taken to evaluate previous air ionization chamber readings obtained in 1961. These earlier measurements were prompted by the construction of the PM-] reactor near Sundance, Natural dose rate levels in this area were found to be 6-8 ur/hr. The ob- served fallout dose rates ranged from 2-5 ur/hr in October, 1962 and 3-4 ur/hr in October, 1963.