Underneath the Entrada Sandstone Formation lies the Navajo Sandstone, a thick layer of light-colored rock that is very prominent in the canyons of southern Utah. Navajo Sandstone is generally much whiter than the reddish Entrada Sandstone, and it tends to erode into deep narrow canyons and smooth-walled cliffs with little fracturing. Entrada Sandstone, on the other hand, has an interesting tendency to erode into unlikely looking pillars and arches of the kind that have made Arches National Park famous. This hike begins very close to the boundary that separates the Entrada Sandstone from the older Navajo Sandstone. At first the canyon is very shallow, but as you proceed downstream the gorge cuts deeper into the Navajo Sandstone and the canyon walls soon become much higher.

You will be following the bottom of Courthouse Wash all the way to the point where Highway 191 crosses it, 0.2 mile before it reaches the Colorado River. The canyon starts out in a general easterly direction, then gradually swings around to the south. Four smaller side canyons join the wash before it reaches the Colorado, all coming in from the northeast, but in each case it is obvious which canyon is the main one. The smaller canyons all lead to an area in the park known as the Petrified Sand Dunes.

Sand, of course, is a by-product of the erosion that carved Courthouse Wash, and the floor of the canyon is filled with a thick layer of it. Walking on the dry, loose sand is tiring, but there is usually a lot of water in the streambed and it is easier to walk in or along the edge of water. Many people take their shoes off and walk barefoot most of the way.

Upper Courthouse Wash
If you want a longer walk you can begin your hike farther north on Highway 191 at the top of upper Courthouse Wash. The upper part of the wash begins on the east side of Highway 191, 5.7 miles north of the park entrance or about 0.2 mile south of the road leading to Dead Horse Point. This route first passes through a narrow canyon in the Entrada Sandstone, and then, after about 2.5 miles, emerges into a wide valley at the bottom of the Entrada Sandstone Formation. There is usually water in the streambed after the first 2.3 miles. Finally, after 7.8 miles, the wash reaches the national park road, where the hike through lower Courthouse Wash begins.