A National Geographic staff photographer since 1990, Mark Thiessen has published numerous feature stories and covers for National Geographic magazine and other National Geographic publications on subjects ranging from Peruvian mummies to the study of human performance.  

In 1996, Thiessen began a personal photography project on Wildland firefighters that took him to the front lines of this phenomenon every summer that led to NGM feature stories on Russian Smokejumpers and recently Alaskan Smokejumpers. Mark’s photographs for the July 2008 National Geographic cover story “Under Fire: Why the West Is Burning” earned first-place recognition by Pictures of the Year International.

Mark documented film director James Cameron’s dive to the ocean’s deepest location at the bottom of the Mariana (or Marianas) Trench. Mark also directs the National Geographic photo studio.