In what year was the national park in which Fan and Mortar Geysers are located signed into law?
Fan and Mortar Geysers: Fan and Mortar Geysers are two geysers in the Upper Geyser Basin in Yellowstone National Park. Yellowstone National Park:  It was established by the U.S. Congress and signed into law by President Ulysses S. Grant on March 1, 1872.
1872