Fortunately, no.
National parks exist for the preservation of sites of natural, scenic, or historic value -- not for amusement. A zip-line would detract from the former.
The National Park covers 1,902 square miles.
It is a 3 hour drive from the Hoover dam to the Grand Canyon viewing areas. The Grand Canyon National Park actually adjoins the Lake Mead Recreational Area which surrounds the reservoir held back by Hoover Dam.
You can find a reliable guide for hiking mules in the Grand Canyon by contacting the Grand Canyon National Park Service or reputable tour companies that offer mule rides in the area.
It covers a total area of 1.902 square miles.
The area of Hells Canyon National Recreation Area is 2,640.525 square kilometers.
Grand Canyon National Park is located in northwestern Arizona. The park covers 1,901.972 square miles of unincorporated area in Coconino and Mohave counties. Fredonia, Arizona is the closest town to the park's North Rim. Tusayan, Arizona is the closest town to the park's South Rim. Tusayan is approximately six miles from the entrance of the Grand Canyon National Park. The city of Flagstaff, AZ is 81 miles from the park's East Entrance.
The area of Somoto Canyon National Monument is 1,703,100.0 square meters.
The area of Red Rock Canyon National Conservation Area is 792.451 square kilometers.
The legal boundaries of the PARK -- from its western edge with Lake Mead National Recreational Area to its eastern edge with the Navajo Reservation -- is about 120 kilometers. The Colorado River travels 446 kilometers between Lee's Ferry and Grand Wash Cliffs, the usual "end points" for The Canyon.
Starvation Canyon (Searles Canyon), Thomas Range,, Utah US
The area of Leslie Canyon National Wildlife Refuge is 11.21 square kilometers.
Glen Canyon National Recreation Area was created on 1972-10-27.