The Hayden Expedition, one of four great surveys of the American West, is largely responsible for the creation of Yellowstone National Park. Led by Dr. Ferdinand V. Hayden in 1871, the expedition included 7 wagons and a party of 34 men. And while the Hayden Expedition wasn't the first Yellowstone exploration - John Colter, Jim Bridger and Henry Washburn toured the area previously - it was the first properly documented journey. Hayden, together with photographer William Henry Jackson, sketch artists Henry W. Elliot and W.H. Holmes as well as painter Thomas Moran, chronicled their findings in a 500-page illustrated account. This impressive document established the area's natural wonders as fact and it created the case for protection in a national park.