Book excerpt: The passage of the 1902 Reclamation Act created a mandate for the federal government to build dams on the Colorado River and its powerful tributaries. By 1920 the US Geological Survey had surveyed the river’s main courses, but still needed accurate charts of the last stretches of deep canyons and white-water rapids, accessible only by boat.Rough-Water Man is the first detailed account of these mapping expeditions by the USGS—the San Juan Canyon in 1921, the upper Green River in 1922, and the Grand Canyon in 1923. Illustrated throughout with period photographs, it is also the personal story of twenty-four-year-old Henry Elwyn Blake Jr., the only boatman to crew on each of the three trips, evolving from novice waterman to expert rapids runner. Drawing on Blake’s diaries, as well as the writings of other USGS surveyors, Rough-Water Man conveys the danger and hardships of navigating these waters with heavy wooden boats and oars. Even today, in rubber pontoons, traversing these canyons is an awesome and exhilarating experience. When Blake and his companions surveyed it, the Colorado ran free and wild from Wyoming to the Sea of Cortez. Westwood gives us mile-by-mile and day-by-day accounts of running these rapids before their canyons were flooded and waters tamed, before the rivers had ever been charted.