ocr: NATIONAL GEOGRAPHIC OnAssignment a GRANI) MANAGED CANYON Making a Big Splash on the Colorado "People always ask ifldid dan- gerous things at the GROGRAPH LI says formerstaff writer Mike Long, whose exploits dur ing his 29-year career ar this magazine-he now works as a freclancer-have included land- ingal 747,canoeing the Alla- gash, racing through the Baja desert in a Volkswagen bug, and interviewing nudists. Yer nothing wasso frightening to Mike (right, at bottom) as being thrown into the deadly churn of the Grand Canyon's Crystal Rapids. "Idon't remember be ing petrified," he: says. 11 just ...