2920925 Tower at Tower Falls, Yellowstone, 1872 (watercolour and gouache over graphite) by Moran, Thomas (1837-1926); 36.2x26.4 cm; National Gallery of Art, Washington DC, USA; (add.info.: Moran was part of Ferdinand Hayden\'s 1871 Geological Survey of Yellowstone to chart the flora, fauna and geology of the largely unexplored west which lead to the establishment of Yellowstone National Park, the first national park of the U.S. ).