“…Field studies made during the Challis project have resulted in modern geologic maps for the entire quadrangle , gravity and aeromagnetic maps for the entire quadrangle (Webring and Mabey, 1981;Mabey, 1982;Mabey and Webring, chap. E, this volume), and extensive geochemical surveys ( Callahan andothers, 1981a, 1981b;Shacklette and Erdman, 1982;Erdman and others, 1983;Fisher and others, 1983). Some of the highlights of these field studies are summarized here.…”