Field studies by graduate students and Branch personnel are conducted in widely varying types of terrain from 

 seashore to mountain top, from desert to tundra and rain forest, and from Arizona to Alaska and India. Trans- 

 portation varies from jeep to dogsled and from boat to airplane. IHere at Trappers Lake, Colorado, at 10,000-foot 

 elevation, researchers are resorting to boat to get to their summer study area. (Photo by Lee E. Yeager.) 



