Hells Canyon, the deepest gorge on earth
By: by William Ashworth.
Publisher: Hawthorn Books
Published: 1977
Place of publication: New York
Language: eng
Number of pages: 246
Subjects: Nature conservation -- Hells Canyon -- History.; Hells Canyon (Idaho and Or.) -- History.; Hells Canyon (Idaho and Or.) -- Description and travel.
Notes: Bibliography: p. 229-235.
Includes index.