Although he had a long, active career in paleontology--he was director of the prestigious American Museum of Natural History from 1935 to 1942--Roy Chapman Andrews is best known for his fossil-hunting excursions to Mongolia in the early 1920's. At this time, Mongolia was a truly exotic destination, not yet dominated by China and rife with political instability. For his expeditions, Andrews used both automobiles and camels, and he had a number of narrow escapes that added to his reputation as a dashing adventurer (he was later said to have been the inspiration for Steven Spielberg's Indiana Jones).
Andrews discovered numerous dinosaur fossils at the formation known as Flaming Cliffs, including specimens of Oviraptor and Velociraptor, but today he's most famous for unearthing the first indisputable evidence of dinosaur eggs (before then, scientists were unsure if dinosaurs laid eggs or gave birth to live young). Even still, he made a huge (if understandable) mistake: Andrews believed he had found an Oviraptor that had stolen the eggs of Protoceratops, but in fact this supposed "egg thief" turned out to be hatching its own young!