Mining operation: chutes, conveyors, miners, railcars; 1930s

VS interior structure with chute being lowered into bin, next chute pulled up, can see man gesturing animatedly / freighter on river moving under steel bridge, ships and maybe mountains in bg / VS miners underground, two work with big motorized drill penetrating into rock wall, men using picks in bg / MS men using drill / railroad cars loaded with rock chunks moving down underground tracks, cars passing in other direction / rocks on conveyor belt as workers separate out rocks / mine opening in mountainside, can see shadow of cameraman; cars exit full of miners; cars come to stop and miners carrying lunch pails jump out and head for exit / MS miners, some looking at camera / looks like huge pile of coal, structures in bg / pan belts filling cars with coal, workers on one, can see D&RCW on car / Note: exact year not known; documentation incomplete