During June and early July northern pocket gophers were trapped on similar rock formations of different ages in Yellowstone Park and in Idaho. These extensive collections are being used to check earlier findings with respect to the variability and intensity of natural radiation and other aspects of the original study reported on in the years since 1961. Samples of parent rock strata were also collected from each of these areas and they are being analyzed for mineral composition. Project Number 112.
Diem, Kenneth L. and Kennington, Garth S.
"Some Aspects of Plant and Animal Distribution as Affected by Geologic Formations,"
Jackson Hole Research Station Annual Report: Vol. 1964
, Article 4.
Available at: http://repository.uwyo.edu/jhrs_reports/vol1964/iss1/4