Why Does Goblin Valley in Utah Look Like an Alien Planet?

The Short Answer

Goblin Valley in Utah looks like an alien planet because thousands of mushroom-shaped rock formations called hoodoos have been carved by 170 million years of erosion, creating a landscape so otherworldly that Hollywood filmed it as an actual alien world — with zero CGI.

What Is Goblin Valley?

Goblin Valley State Park sits in a remote corner of southeastern Utah, a wide desert basin unlike almost anywhere else on Earth. The valley floor is packed with thousands of short, bulbous rock formations — each one eerily distinct, some clustered together, others standing alone like silent sentinels. Locals and visitors call them goblins. Geologists call them hoodoos. Either way, they look like they belong on another planet.

The valley is not a minor roadside curiosity. It spans roughly three square miles of this strange sculpted terrain, and walking through it feels genuinely disorienting — as if the scale and rules of the landscape have quietly shifted.

How Do Hoodoos Form?

The shapes come down to a simple but powerful geological process. Each hoodoo has a harder sandstone or iron-rich cap on top that resists weathering more effectively than the material beneath it. The softer mudstone and siltstone below erode faster — worn away by rain, wind, and freeze-thaw cycles over enormous spans of time. The cap protects whatever sits directly underneath it, while everything around it gradually disappears. The result is a mushroom shape: wide and rounded on top, narrower at the base.

Multiply that process by thousands of formations across the same basin, each eroding at a slightly different rate, and you get Goblin Valley — a crowd of misshapen rock figures frozen mid-formation.

170 Million Years in the Making

The rock itself originated during the Jurassic period, roughly 170 million years ago. At that time, the region that is now landlocked Utah sat along the shoreline of an ancient inland sea. Layers of sediment — sand, silt, and mud — accumulated along that coastline and were slowly compressed into rock over millions of years.

The formations you see today are carved from that ancient seafloor sediment. What looks like an alien desert was once a beach.

Hollywood Noticed

The 1999 science fiction comedy Galaxy Quest needed a convincing alien planet for one of its key scenes. The production team chose Goblin Valley. No set construction. No CGI enhancement. The valley was filmed largely as it exists in nature, and audiences accepted it instantly as another world. That says something significant about just how far outside ordinary human landscape experience this place really is.

The Destruction That Almost Erased 170 Million Years

In October 2013, two adult Boy Scout leaders visiting Goblin Valley deliberately toppled one of the ancient hoodoo formations, filmed themselves celebrating, and posted the video online. The rock had stood for an estimated 170 million years. It was gone in seconds.

The incident triggered immediate public outrage and criminal charges. Both men were charged with felony counts related to the destruction of public property. The case became a sharp reminder that these formations are not renewable on any timescale meaningful to human life. Once destroyed, they are gone permanently.

Why Goblin Valley Matters

Goblin Valley is protected as a Utah State Park, but its formations are fragile. The same softness in the rock that makes hoodoos possible also makes them vulnerable. Visitors are encouraged to walk among the formations on designated paths rather than climbing or touching them directly.

For anyone interested in geology, deep time, or simply landscapes that challenge the imagination, Goblin Valley is one of the most remarkable places on Earth — which is precisely why it keeps getting mistaken for somewhere else entirely.