His works include landscape photographs in deserts of the American southwest, still life studies in communities of marginalized inhabitants in New Mexico, and portraits of Tibetan refugees living in India.
[5] Photographer Mary Ellen Mark called Zimmerman's Desert works "a unique vision of the beauty, poetry and power possible in great landscape photography".
Between sand and sky, earth and heaven, the images of Last Refuge are above all a testimony to man's resilience and spirit, living in a damaged territory.
[10] Robert Hariman writes (in his essay "The Last Individuals") "The portraits are profoundly evocative precisely because they draw on deep wells of moral and artistic truth.
In 2011 Zimmerman co-founded the Himalayan Art Centre – a school providing free education in visual story-telling through photography and filmmaking in Dharamshala, India.