00991cam a2200253 4500 1297812160 TxAuBib 20090102120000.0 050314s2001||||||||||||||||||||||||eng|u 9780060002039 0060002034 CO 4217 c.wall TxAuBib Powell, John Wesley. Down the great unknow : John Wesley Powell's 1869 journey of discovery and tragedy through the Grand Canyon. NY : HarperCollins, 2001. 4 sound cassettes (6 hr.) Author: Edward Dolnick. Read by Sam Tsoutsouvas. 20050315. Powell, John Wesley 1834-1902 Travel Travel Arizona Grand Canyon. Explorers United States Biography. Grand Canyon (Ariz) Discovery and exploration Description and travel. Colorado River (Colo.-Mexico) Discovery and exploration.