Abstract
In July and August of 1969, 33 Microtus pennsylvanicus, 20 M. montanus, 21 Clethrionomys gapperi, 3 Zapus princeps, and 19 Sorex sp. were trapped in two areas in Jackson Hole, Wyoming by Tim W. Clark. Several milligrams of hair from the mid-dorsal region of each animal was collected for trace element analysis at the National Reactor Testing Station in Idaho by the author. Project Number 170.