The fast muscular waters of the Rockies are the particular delight of JOHN HODGDON BRADLEY,author, geologist, and angler, who at the urging of the Atlantic now discloses his favorite haunts and bypaths to those who would like their first taste of Western mountain trout. Mr. Bradley graduated from Harvard in the class of 1921, took his Ph.D. at the University of Chicago in 1924. and since then has taught geology at Harvard, at Chapel Hill, in Montana, and at the University of Southern California.