With a stroke of a pen, he preserved close to a million acres of canyon county, unique both to our nation and the world. The Antiquities Act is a powerful piece of legislation. The resources protected also tend to be different.
National monuments tend to preserve singular resources.
Muir visited the Petrified Forest in 1905 and was enchanted by the stark landscape of the Painted Desert and the preponderance of petrified wood. Unfortunately, others saw great economic opportunity in the exploitation of this unique resource. In December of 1906, at Muir's suggestion, Roosevelt created Petrified Forest National Monument. Ultimately, in 1962, Congress added additional lands to the monument and it became Petrified Forest National Park. In 1908, also at Muir's prodding, Roosevelt created Grand Canyon National Monument.