 While on freelance assignment for "National Geographic" in Darfur, Sudan, he was ambushed and imprisoned for more than a month in 2006 by pro-government military forces.In the fall of 2009, Salopek taught an undergraduate seminar on reporting from the developing world at Princeton University as part of Princeton's Journalism Program.In January 2013, Salopek embarked on a walk along one of the routes taken by early humans to migrate out of Africa, initially scheduled to take seven years.