First known as Mukuntuweap National Monument, Zion was first established in 1909. Unfortunately the name was changed to the name used by the Mormons just before it was established as a national park in 1919. American Indian tribes had inhabited the area for thousands of years like most of the area - leaving behind artifacts of clay pots, baskets and more.
Lower in elevation, temperatures get up into the 100s and with two million visitors a year, it is hot and crowded. I read an article that said Zion is number 8 in the top 10 visited national parks. One main road traverses the park and includes a mile long tunnel. Built before huge motor homes were common, the tunnel has size restrictions and we were glad to have left SLOTH outside the park. Traffic is often backed up and campgrounds fill by mid morning. A free shuttle service is the only way through scenic Zion Canyon, stopping at the lodge, trailheads and waterfalls. Weeping Rocks is a popular short hike, water seeps from porous sandstone and nourishes ferns, wildflowers and moss known as the the hanging gardens.
My favorite area was Checkerboard Mesa with majestic criss-crossed patterns resembling a massive checkerboard. The fissures are deep horizontal scratches due to wind and vertical cracks from weathering, repeated freezing and thawing.
Flash floods caused by water plummeting down the deep slot canyons is a major safety issue. The storm we watched start at Grand Canyon's north rim had dumped enough water in the Zion to drown several unsuspecting hikers. We were there the following day but did not learn of the reason for the search teams we saw along the river until we returned to Bryce Canyon.