Ah-Shi-Sle-Pah Wilderness Study Area

With its muted colors and striking geology, this unusual landscape feels like a martian planet. Pale, mushroom-shaped hoodoos loom above the rocky earth like enormous alien trees. Petrified tree stumps and ancient bones speckle the badlands like prehistoric markers of its long-gone inhabitants.

Located in the arid San Juan Basin of northwest New Mexico, the Ah-Shi-Sle-Pah Wilderness Study Area is located on 6,563 acres of public Bureau of Land Management land. It’s a hidden wonder of weathered rock formations often referred to as hoodoos (not to be confused with witchcraft or the evil eye), tent rocks, fairy chimneys, earth pyramids, or mushrooms.

Geologically, the area is comprised of layers of sandstone, shale, mudstone, and bituminous coal that were deposited 75 million years ago during the late Cretaceous era. A whopping 75,000 millennia of wind, water, and ice weathering and eroding the layers are responsible for the surreal and alien-esque landscape.

Because of its geologic age and climate, the area is rich with animal and plant fossils. The remains of prehistoric crocodiles, turtles, fish, and dinosaurs are sprinkled throughout the land. You’ll also see petrified wood, including numerous upright tree stumps with roots. Fossils are not allowed to be collected.

While it's somewhat challenging to get there, visitors are rewarded with a tranquil, if not dreamlike, environment which is easy to navigate. Although the formations extend for six miles along the Ah-Shi-Sle-Pah Wash, the most accessible and picturesque formations are within one to two miles of the parking area and can be seen within half a day of easy walking along the generally flat terrain.