Cody Townsend's white backpack in the Fifty Project episodes for Mt. St. Elias (and other episodes like Mt. Rainier), is the HyperLite 5400 Porter backpack. He and Dan Corn, Nick Russell and cinematographer Bjarne Salen can also be seen using the HyperLite Porter Stuff pocket attached to the 5400 Porter backpack in the Mt St. Elias episode.
You can also read a Tweet from Hyperlite here that says: "Episode 20 of the Fifty Project takes Salomon Freeski athlete Cody Townsend, his 5400 Porter, and professional surfer Ian Walsh up Mt. Rainer for some high alpine education and weather watching during their journey to summit all 50 Classic Ski Descents"