Stock photography, photos: Tree on hillside in winter Stock photos of A oak tree on a snow covered winter hillside. Photograph: © Dan Creighton Click for a larger image and more information Keywords associated with this stock photo: environment, ecosystem, concepts, plants, season, concept, outdoors, conceptual, scenery, beauty, tree, land, habitat, ecology, beautiful, scenic, brown, green, nature, trees, US, world regions & countries, North America, United States of America, PA, Pennsylvania, USA, Chester County, America