Stock photography, photos: Two Boulders on Prairie Stock photos of Two large boulders lie on the open prairie. Bluestem Prairie Scientific & Natural Area, Minnesota. Photograph: © Matthew Thalman Click for a larger image and more information Keywords associated with this stock photo: boulder, boulders, rock, rocks, prairie, grassland, America, Bluestem Prairie, Bluestem Prairie SNA, Minnesota, North America, Scientific & Natural Area, Scientific & Natural Areas, United States, United States of America, US, USA