Fiery Furnace: Arches' Permit-Required Sandstone Maze

Standing at the Fiery Furnace viewpoint off the main park road, the formation looks like a grid of fins pressed close together. Orange walls, narrow shadows between them. From up here it resembles a maze. Inside, it is one.

Fiery Furnace is one of the few places in Arches National Park where you move through the geology rather than looking at it from the outside. The permit requirement exists for two reasons: the terrain genuinely disorients people, and the rock surfaces and soil inside are fragile enough that foot traffic needs to be managed.

What the Formation Actually Is

The fins are walls of Entrada sandstone, roughly parallel, separated by passages that range from a few feet wide to tight squeezes that require turning sideways. The tallest fins reach 80 feet. Looking up from a narrow slot with walls on both sides creates a scale shift that photos don’t fully capture.

The name comes from what happens at sunset. The fins face west and catch the last light of the day, turning deep orange-red across the whole formation. “Furnace” is accurate in summer too. The passages trap heat. Midday temperatures inside can climb several degrees above the air temperature outside.

From a distance the fins look like you could walk through them in a straight line. Inside, that logic falls apart fast. The passages curve, dead-end, and connect through openings that aren’t visible until you’re standing in front of them. It’s disorienting by design, geologically speaking. The fins formed as water eroded vertical cracks in the sandstone over millions of years, widening some and leaving others as thin walls.

The Permit System

You have two options: a ranger-led tour or a self-guided permit.

Ranger tours cost $16 per person and run about 3 hours. Group size is capped at 12. The ranger picks the route, which varies by guide and by conditions. You’ll see multiple arch formations inside the maze, some of which don’t appear on any trail map because they’re unmarked. The ranger covers the geology, the fragile cryptobiotic soil crust (black, lumpy, looks like dirt clumps), and the potholes that hold water and micro-organisms that take decades to recover from a single footstep.

Self-guided permits cost $10 per person. Before you enter, you watch a mandatory orientation video at the visitor center that covers navigation basics, resource protection, and what to do if you get turned around. The video isn’t optional. Rangers check that you’ve completed it.

Both types sell out months in advance during peak season. April through October is peak. Book through recreation.gov as early as possible. If you’re planning a spring or fall trip, 2-3 months advance booking is not an exaggeration. Last-minute permits are rare.

What to Expect on the Ranger Tour

The tour starts at the Fiery Furnace trailhead on the main park road. The ranger leads the group into the formation from the north end and routes through the main passages. Plan on moderate scrambling: stepping over low rock ledges, climbing short sections of smooth slickrock, and squeezing through passages. You don’t need technical climbing ability, but you do need to be comfortable moving on uneven rock.

The ranger stops at several formations inside the maze, including arches that aren’t marked on any map and alcoves that show desert varnish and, in some cases, ancient hand prints. The geology commentary is worth paying attention to. Fins don’t form in isolation and the ranger explains how the whole formation connects as one erosional system.

Some sections of the route require you to step carefully around cryptobiotic soil crust. The crust looks like dry, bumpy ground but it’s a living community of algae, fungi, and bacteria that stabilizes the soil and prevents erosion. One footstep can destroy decades of growth. The ranger points out where it is and routes the group around it.

Self-Guided Navigation

No trails are marked inside Fiery Furnace. If you go self-guided, download the AllTrails track before you enter. The main navigable route through the maze is covered, but GPS accuracy can degrade next to tall fin walls. Don’t rely solely on your phone.

The most important skill inside is staying aware of your general direction. The fins run roughly north-south. If you’re moving perpendicular to the fins, you’re crossing the formation east to west or vice versa. If you find yourself always moving parallel to fin walls without crossing them, you’ve likely turned into a dead-end passage.

People get disoriented here every season, including experienced hikers. The NPS has conducted search and rescue operations inside Fiery Furnace. If you go self-guided, tell someone your plans, bring more water than you think you need, and carry a downloaded offline map in addition to the AllTrails track.

Photography Inside the Fins

The narrow passages create some of the best light in the park. Midday, which is usually the worst time for outdoor photography, actually works well inside the formation. Light falls from directly above and hits the canyon floor in columns between the walls, creating contrast between lit passages and shadowed fins.

Morning and late afternoon create a different effect: warm orange light on the upper edges of the fins, cool shadow below. The passages photograph well with a wide angle because the fin walls frame the shot naturally. Shooting upward from inside a narrow slot gives you a version of the classic “canyon walls” composition, except the walls are standing fins rather than cut canyon.

Potholes filled with water reflect the fins above them. They’re worth photographing and also worth not stepping in. The water holds microorganisms and leaving boot contamination behind harms the pothole community in a small but real way.

The Free Option

If permits are sold out or the timing doesn’t work, the Fiery Furnace viewpoint is roadside, no permit needed. You get a clear overview of the entire formation from a slight elevation above it. You can see the layout of the fins, the shadows in the passages, and the scale of the maze.

The viewpoint won’t give you the inside experience, but it’s a legitimate stop on its own. Sunset from the viewpoint, when the fins go full orange-red, is one of the more visually dramatic moments in the park.

If you’re visiting Arches for the first time and weighing which experiences to prioritize, the ranger tour of Fiery Furnace rewards the extra planning more than almost any other hike in the park. The permit cost and advance booking are the barriers. The experience on the other side of those barriers is completely different from anything else at Arches.

Book the ranger tour first, then plan the rest of your trip around the date you get.