1853 - 1937
- Associate editor and later editor-in-chief of Century magazine, which published many of John Muir's articles.
- After a camping trip with Muir in 1889, Johnson is credited with encouraging Muir to write the articles which led to the creation of Yosemite National Park. While Muir inspired the nation with his writing, Johnson and his influential eastern friends lobbied Congress to establish the park.
- "The Treasures of the Yosemite," by John Muir, The Century Magazine, August 1890.
- "Features of the Proposed Yosemite National Park" by John Muir, The Century Magazine, September 1890.
- Johnson also campaigned with Muir in the unsuccessful effort to stop the damming of Hetch Hetchy Valley in Yosemite National Park.
- Johnson's autobiography, Remembered Yesterdays, tells of his friends and acquaintances, including not only John Muir, but Theodore Roosevelt, John Burroughs, Nikola Tesla, Mark Twain, and Rudyard Kipling, to all of whom he introduced John Muir.
- John Muir as I Knew Him by Robert Underwood Johnson from Sierra Club Bulletin, 1916.