In a career forged in the saddle on scout duty along the Rio Grande, Arthur Hill witnessed dramatic changes from 1947 to 1974. Whether inspecting brands, deterring smugglers of everything from cattle to candelilla wax, or giving chase on horseback across merciless terrain often into Mexico Hill found himself immersed in a world that straddled centuries as well as cultures.Promotion to sergeant of Ranger Company B in 1957 took Hill to Dallas, where he brought his brush-country methods to bear on urban crimes. Yet after only a year, and despite the opportunity for advancement to captain, Hill...