Sam Demientieff is an Athabascan who was born in Holy Cross, Alaska in 1939, and grew up in Nenana and Fairbanks, and along the Yukon and Tanana Rivers where his father ran a barge service. He graduated from high school at Copper Valley School in Glennallen, and earned a certificate in mineral petroleum technology from the University of Alaska Fairbanks. Sam worked for Fairbanks Native Association, Doyon, Ltd. and retired from the Bureau of Indian Affairs. Sam has extensive knowledge of interior Alaska rivers, going back to his boyhood when he traveled the rivers with his father to his own subsistence travel by boat in summer and by snowmachine in winter. Sam lives on the Chena River in Fairbanks, and spends many hours traveling up and down the Tanana River in both winter and summer. He is a keen observer of water flow, channel changes, and changing ice conditions. Sam has served as an expert consultant on local observations and understanding of the environment for many scientific projects. He has participated in the Dangerous Ice Project Jukebox and the Climate Change Project Jukebox.