of the Powell Expedition. The Kolb Brothers, Emery and Ellsworth, built a photographic studio on the South Rim at the trailhead of Bright Angel Trail in 1904. Hikers and mule caravans intent on descending down the canyon would stop at the Kolb Studio to have their photos taken. The Kolb Brothers processed the prints before their customers returned to the rim. Using the newly invented Pathé Bray camera in 1911–12, they became the first to make a motion picture of a river trip through the canyon that itself was only the eighth such successful journey. From 1915 to 1975 the film they produced was shown twice a day to tourists with Emery Kolb at first narrating in person and later through tape (a feud with Fred Harvey prevented pre-1915 showings). Protection efforts By the late 19th century, the conservation movement was increasing national interest in preserving natural wonders like the Grand Canyon. National Parks in Yellowstone and around Yosemite Valley were established by the early 1890s. U.S. Senator Benjamin Harrison introduced a bill in 1887 to establish a national park at the Grand Canyon. The bill died in committee, but on February 20, 1893, Harrison (then President of the United States) declared the Grand Canyon to be a National Forest Preserve. Mining and logging were allowed, but the designation did offer some protection. President Theodore Roosevelt visited the Grand Canyon in 1903. An avid outdoorsman and staunch conservationist, he established the Grand Canyon Game Preserve on November 28, 1906. Livestock grazing was reduced, but predators such as mountain lions, eagles, and wolves were eradicated. Roosevelt added adjacent national forest lands and re-designated the preserve a U.S. National Monument on January 11, 1908. Opponents, such as holders of land and mining claims, blocked efforts to reclassify the monument as a National Park for 11 years. Grand Canyon National Park was finally established as the 17th U.S. National Park by an Act of Congress signed into law by President Woodrow Wilson on February 26, 1919. The National Park Service declared the Fred Harvey Company to the official park concessionaire in 1920 and bought William Wallace Bass out of business. An area of almost 310 square miles (800 km²) adjacent to the park was designated as a second Grand Canyon National Monument on December 22, 1932. Marble Canyon National Monument was established on January 20, 1969, and covered about 41 square miles (105