Checkerboard Mesa looks as though someone has scored a giant loaf of bread with a ruler. The great dome of Navajo sandstone is crossed by two sets of lines, one set horizontal and curving, and the other vertical and straight, and the effect is a checkerboard pattern that runs the height of the rock. The horizontal lines are the ancient dunes, the sloping layers laid down by wind in a desert some 190 million years ago. The vertical cracks came later, as the rock shrank and the stone dried and split, and weathering has deepened both.
The pull-out is right beside the Zion-Mount Carmel Highway, a short distance east of the tunnel, and it is one of the easiest geology lessons you will ever get. You do not need to climb or walk; you can sit on the bike and look. The mesa is the first thing you see after the road exits the narrow canyon, and the sense of opening out is wonderful. On a clear day, in the right light, the sandstone turns from cream to peach to orange, and the shadows in the cracks pick out the pattern.
The riding here is the best bit of the highway. East of the tunnel, the road is rolling and open, with broad curves and good visibility across a landscape of white slickrock, juniper and pinyon pine. The speed limit is low, there are bighorn sheep and mule deer, and the sky is huge. Drive time to Mount Carmel Junction is relatively short. In the early morning there are few people, and in the afternoon the hot sun and wind can make the roadside feel exposed, so a layer and a water bottle both help.
The parking area is small and the access is easy, so it fills up fast on summer days. Mount Carmel Junction, about twenty minutes to the east, has a small fuel stop and cafes, and Kanab, further east, is a larger town with more choice. Springdale, on the west, has everything but is a long way back. Keep an eye out for livestock and sudden weather, particularly in thunderstorm season.