As a 17-year-old living and working in the Amazon basin, Stan Brock found himself in need of a doctor after he was thrown from a horse. "I had a head-on collision with the side of a corral," Brock said. "I was told, 'The nearest doctor is a 26-day walk away.'?" That incident and others stuck with Brock, now 74. Through the intervening decades, he managed a 4,000-square-mile cattle ranch in South America, co-hosted NBC's "Wild Kingdom" and made what he calls "a few bad movies."