First it was declared a national monument in early 1900's. Then in 1919, named a national park which it classified as a historical & scenic area that is used for conservation purposes protected by the federal government
And here i was going to say google it lol
Because of the geographical, ecological, historical, antropological and even topographical importance of it. There's no other place like it above sea level. Giving it park status allows government to control things ecosystem protection. You know that the grand canyon is one of the few places in the entire country where you can have a total visibility of the night skyline? This is because of the restrictions/bans regarding electrical and transmission towers and systems on the reserve. More information here : https://www.nps.gov/grca/learn/historyculture/index.htm
Thanks! Your answer is awaiting moderation.