Riis approaches his work as a trained biologist and core conservationist, believing that photographs can give wild animals and places a voice in our culture. Riis established himself as a photojournalist during his pioneering work on the Grand Teton pronghorn migration, documenting the migration for the first time, and campaigning for 6 wildlife highway over and under passes which are now being built with a completion date in late 2012. Riis received an Emmy in 2011 for his pronghorn cinematography on the NG Great Migrations series.

Riis lives alone in a cabin that he built on the prairie in South Dakota on his great grandparents homestead.