National Geographic : 1926 Jan
Photograph by Captain A.W.Stevens GREEN RIVER, WYOMING, AS THE AIRMAN SEES IT Mountain water, flowing over green shale, assumes the light to deep shades of green which give both theriver and the town itsname. The river bluffs have been carved by the elements into curious forms, such as natural monuments and castlelike structures, light green below and dark brown above. The upper beds, being harder than the lower ones, make protecting caps for the pinnacles. Major J.W. Powell started in1869 from the little town of Green River for his daring exploration of the Colorado's canyons.