There are 100 areas known as National Monuments in the United States. These are areas that the President set aside for special protections, a right given to the President under the Antiquities Act of 1906. Many National Parks started off as National Monuments. Most of these areas are managed by the National Park Service, but some are managed by the US Forest Service, Bureau of Land Management, US Fish & Wildlife Service, and even the Armed Forces Retirement Home and National Oceanic and Atmospheric Administration have a hand in managing one monument each. Many National Monuments are co-managed by two or more agencies.
The first National Monument was Devil's Tower in the state of Wyoming. It was established by President Theodore Roosevelt in 1906. Bill Clinton created the most National Monuments, 16, followed by Jimmy Carter who designated 15. Most of these areas were already federal land - the National Monument designation just brings additional special protections to the area.
55 National Monuments are areas of natural importance. There are also some that protect Native American and historical sites. Arizona has the most National Monuments, followed by New Mexico.
Here is the list of National Monuments, many of which have a SummitPost page dedicated to them.
"I am in love with this world. I have nestled lovingly in it. I have climbed its mountains, roamed its forests, sailed its waters, crossed its deserts, felt the sting of its frosts, the oppression of its heats, the drench of its rains, the fury of its winds, and always have beauty and joy waited upon my goings and comings."