THE WESTERN DESERTS AT NIGHT Photographs by Jonathan PJ Smith of The Environment Makers Trona Pinnacles at Night Trona Pinnacles, just outside Death Valley, were formed in the same manner as the famous tufas of Mono Lake. Nighttime Joshua Trees at the Mojave National Preserve Joshua Trees! They define parts of the Mojave Desert and the largest Joshua Trees forest is found at Mojave National Preserve. Saguaro Cactus at Night The night sky and iconic Saguaro Cacti pretty much define the deserts of Arizona.