Castle Trail
What to Expect
Safety Advisory
There is no shade on this entire trail. Summer surface temperatures on the clay can exceed what the air temperature suggests by a wide margin — heat exhaustion is a real risk from June through September. Start before 7 AM or save it for spring and fall.
The trail can be faint in spots where it crosses open clay flats. Cairns mark the route, but in poor visibility or after rain (when the clay becomes impassable grease), it is easy to lose the path. Download the trail to your phone's offline maps before you start.
Trail Details
Pro Tips
Set up a car shuttle by dropping a vehicle at the Fossil Exhibit Trail parking area before driving to the Castle Trail trailhead at the Door/Window parking lot — walking this as an out-and-back doubles it to twenty miles, which is a very different day.
Carry at least three liters of water per person. There is zero reliable water on this trail, and the exposed clay terrain radiates heat like an oven even on mild days.
The most photogenic formations cluster in the first two miles out from the Door/Window trailhead — if you start at dawn, the low-angle light turns the banded clay walls into striped gold and purple. The middle section is flatter and more monotonous, so front-load your camera time.