You can find some dried food good for backpacking in almost any grocery store, but the stores below have a really good bulk section.
Winco Foods
4275 Barger Dr. Eugene, OR
1920 Olympic St. Springfield, OR
Market of Choice
67 W. 29th Ave. Eugene, OR
1960 Franklin Blvd. Eugene, OR
1060 Willakenzie Rd. Eugene, OR
2580 Green Acres Rd. Eugene, OR
Fred Meyer
3333 W. 11th Ave. Eugene, OR
60 Division Ave. Eugene, OR
650 Q St. Springfield, OR