yellowstone national park, midway geyser basin, boardwalk at grand prismatic spring, wyoming

algae america american attraction basin beautiful blue boardwalk brown color colorful colour colourful deposits destination display elevation enjoy geothermal geyser grand heat higher hike hiking hill hot landscape midway mountains national nature nearby orange outdoor outdoors park parks people prismatic rocky runoff spectrum spring springs states steam thermal tourism tourist tourists travel travertine united usa visible volcanic water waters west western wild wilderness wyoming yellowstone natural environment