Written by Jason Epperson

There’s one natural rock arch that’s known better than all others in the US, in fact, it’s on the state of Utah’s license plate. It had its own postage stamp, and the 2002 Winter Olympics torch relay passed through it. On this episode of America’s National Parks, Delicate Arch, and the strange history of attempts to protect it at Arches National Park.

Rock arches are wonders of the natural world. The idea that they were organically formed seems almost impossible, but of course, they are. The technical definition of a natural arch is a “rock exposure that has a hole completely through it formed by the natural, selective removal of rock, leaving a relatively intact frame.”

There are about 2000 significant natural arches in the US. A “significant” natural arch has two orthogonal opening dimensions with a product of 10 square meters or more. Of course, there are many more smaller arches.

There’s actually an entire society of arch-lovers, called the Natural Arch and Bridge Society, whose $16 membership fee gets you four issues annually of “Span” magazine. You can find more info than you ever thought you could find about rock arches on their website. From the different classifications, measurement techniques, how they’re formed, how they get named… it’s a fascinating rabbit hole to go down if you have some time to kill.

Delicate Arch

Delicate Arch

Arches National Park is home to over 2,000 natural arches that have been carved from tall, fin-like sandstone formations over the course of millennia.

Sandstone is made of grains of sand cemented together by minerals, but not all sandstone is the same. Entrada Sandstone was once a massive desert of fine-grained shifting dunes. The nearly spherical grains, when compressed together, formed a rock that is highly porous.

The Carmel layer, just beneath the Entrada, iss composed of a mix of sand and clay. Clay particles fill in gaps between the sand grains, making the rock denser and less permeable.

Deep below the surface rests a thick layer of salts. Compressed by the tons of rock above it, the salt projected upward, creating domes. The rock layers covering the domes cracked into a series of parallel fins.

Drops of rainwater soaked into the porous Entrada sandstone dissolving the bonds between the sand. The water then puddled just above the Carmel layer, eroding a cavity. The two layers expand when frozen, prying the rock apart, forming an opening. Wind then takes over, like a sandblaster, enlarging the opening and wearing away the exterior of the arch.

The most famous of these arches is the 60-foot tall rock structure that was called by local cowboys “the Chaps” or “the Schoolmarm’s Bloomers.” Today we know it as Delicate Arch, and it attracts nearly 1.5 million visitors per year. The opening is 46 feet high and 32 feet wide, making it the largest free-standing arch in the park.

Delicate Arch wasn’t within the boundaries of the original Arches National Monument in 1929; it was added when the monument was enlarged in 1938. Still, even then, it was the most recognizable feature of the park.

As its name suggests, Delicate Arch is fragile, and the National Park Service goes to great lengths to ensure that visitors don’t degrade it. But despite their best efforts, the same forces that shaped Delicate Arch will one day destroy it, just like the nearby Wall Arch, which collapsed in 2008.

Delicate Stabilization

During his first winter at Arches, ranger Jim Stiles spent his days ransacking file cabinets and soaking up every bit of information he could find. One day he came across a folder labeled “Delicate Arch Stabilization Project.” Inside he found a decade of letters and reports discussing the state of the Delicate Arch, and whether or not it should be saved from eventual collapse by the Park Service.

Stiles found that, in 1947, a park custodian wrote to the regional director about the eroded condition of the east leg of Delicate Arch, suggesting that measures be taken to stabilize it.

For the next few years, Park Service officials would discuss the idea, but it was never taken very seriously, except by those who were concerned it could fall on a group of tourists.

But the idea gained traction when Southwest Regional Assistant Director Hugh Miller visited the arch. Miller backed a plan to apply a plaster jacket over the weak point, and then painting it to match the red rock of the arch. The National Park Service’s citizen advisory board opposed stabilization of any formations, but Davis was adamant that Delicate Arch should be an exception for its unique qualities, comparing it to a museum exhibit, according to one of the letters Stiles found.

The decision had been made by park service brass. The arch would be stabilized. But the question of how was still up for debate. A plater cast likely wouldn’t last long in the elements. Representatives from the Engineering Division and the Landscape Architectural Division met to discuss. Ridiculous ideas were floated, such as spraying it with a fixative, perhaps Elmer’s Glue or Lady Clairol Spray-Net. More serious options were a concrete collar, like the plaster jacket, or, most promising, a silicone epoxy spray.

But Park Superintendent Bates Wilson wasn’t sold. He, and others saw that messing with the arch could backfire. Not only would any attempt to stabilize it most certainly cause lasting damage, but the whole thing could also collapse during the effort. Besides, the real danger to the arch wasn’t its imminent collapse, which a band-aid would barely delay. It was graffiti. “The increasing desire of fools to carve their names in public places has reached the highest level possible in Arches at Delicate Arch,” he wrote.

But the regional office ordered the park to test the silicone epoxy, and dozens of samples were ordered from manufacturers. Instead of arguing with the bosses, Bates took a different approach. The slow roll. In fact, the many memos and letters that Stiles found were curiously void of Bates’ name, and the entire staff of Arches remained fairly quiet on the matter.

Memos kept coming in from the regional office asking for updates. Arches did not reply. The regional office asked if more money was needed. Arches did not reply. Finally, the General Superintendent sent Bates a memo saying “Will you please make a special report on this project at your very earliest convenience?” The park staff finally responded, saying they mixed the solution back in February and it was supposed to be applied within 90 days. Now, with winter closing they’d need to order a new mixture. A fine excuse.

Arches successfully fended off the General Superintendent. His memos ceased, but then, a few years later a concerned citizen wrote the National Park Service Director suggesting that a clear, erosion-resistant material be sprayed on the arch. Everyone remembered again.

Bates fended it off again, convincing his senior officials that exposure to the weather had caused the tested coatings to turn white, or scale off, and that much more experimentation would be needed.

And that’s where the idea died, as Bates Wilson outlasted his superiors.

One day, Delicate Arch will fall, as all free-standing arches do. It could be tomorrow, it could be a thousand years from now, but it will now fall as a part of its natural life cycle.

Arches National Park

Arches National Park hosts over 2,000 natural stone arches, along with hundreds of soaring pinnacles, massive fins and giant balanced rocks, set under the blue skies of southeast Utah.

It’s part of the Colorado Plateau, a “high desert” region that experiences temperature fluctuations over 40 degrees in a single day. The most popular seasons are spring and fall, when daytime highs average from 60 to 80 degrees. Summer temperatures often exceed 100 degrees, making hiking difficult under the unshielded sun. Winters bring snow and cold, offering the chance for photos with the arches draped in a blanket of white.

For the quick visit, there’s a scenic drive and short trails to viewpoints. But a longer visit is much more rewarding, because some of the best formations take a bit longer of a hike. Arriver early in the morning or late in the afternoon, as parking at most trailheads is full for most of the day. You can even check the park’s webcams to see the current line at the entrance station.

At Lower Delicate Arch Viewpoint, you can see Delicate Arch at about one mile’s distance. The nearby Upper Viewpoint, a half-mile walk with stairs, offers a slightly less obstructed view.

The trail to see Delicate Arch up close is 3 miles roundtrip and climbs 480 feet in elevation. On busy days, there is additional parking at the Delicate Arch Viewpoint parking lot. You’ll have to hike an additional mile along the road to the trailhead. The trail can be very busy, with hundreds of people at Delicate Arch for sunset.

Make sure to carry plenty of water and a proper hat and clothing for the hot summer sun or cold winter air.

Devils Garden Campground, 18 miles from the park entrance, is open for reservations March 1 – October 31. All sites are usually reserved months in advance. Between November 1 and February 28, sites are first-come, first-served. Facilities include drinking water, picnic tables, grills, and both pit-style and flush toilets.

There are many commercial campgrounds in the Moab area, and backcountry camping is permitted in a select few locations within the park.

Learn More

Links to some of the resources we used and the website links we mentioned in this episode. 

Arches National Park – National Park Service Website

The Stabilization of Delicate Arch – Ranger Jim Stiles’ article on his findings

The Natural Arch and Bridge Society