Las Vegas is located in the middle of 5 national parks – close enough that you can choose one and make a day trip out of it.
Those national parks include Death Valley in California, Bryce Canyon and Zion Parks in Utah, and two Grand Canyon National Parks in Arizona.
The North Rim and South Rim of the Grand Canyon are operated by the National Park Service, and each is about 5 hours from Las Vegas by car.
The North Rim is closed from late September to May. Because of the high elevation, the roads are closed by several feet of snow.
The South Rim is at a lower elevation, and even though it gets a little snow during the winter, it is open year-round. It is easier to get to from other large cities such as Phoenix and Los Angeles, and the South Rim hosts over 4 million visitors a year.
Much closer to Las Vegas, only 2 and a half hours away by car, is Grand Canyon West. The Skywalk is there, and last year Grand Canyon West Rim hosted nearly 1 million visitors.