Collapse of "Wall Arch" Proves Gravity Does Work at Arches National Park

Wall Arch is no more at Arches National Park after giving in to gravity earlier this week. NPS photos.

One minute it was there, the next it was gone.

The collapse of "Wall Arch" at Arches National Park proves once again that gravity does work, even though you might wonder after gazing at the "rockitecture" of this dazzling Utah park.

Wall Arch, long a key attraction along the park's Devils Garden Trail, collapsed sometime overnight August 4. And since rock has continued to peel off of the collapsed arch, officials have been forced to temporarily close the popular trail just beyond Landscape Arch.

On Thursday representatives from both the National Park Service Geologic Resources Division and the Utah Geological Survey visited the site and noted obvious stress fractures in the remaining formation. Rock debris has completely blocked this section of the trail. The closure will remain in effect until visitor safety issues can be resolved.

First reported and named by Lewis T. McKinney in 1948, Wall Arch was a free-standing arch in the Slickrock member of the Entrada sandstone. The opening beneath the span was 71-feet wide and 33-1/2 feet high. It ranked 12th in size among the over 2,000 known arches in the park.

All arches are but temporary features and all will eventually succumb to the forces of gravity and erosion. While the geologic forces that created the arches are still very much underway, in human terms it’s rare to observe such dramatic changes.

No one has reported observing the arch collapse and there were no visitor injuries.


thank God there are people in charge out there, that know its a natural thing, and not some nut who wants to coat all the arches with super glue so that the park remains the same forever. We are constantly evolving.

Kurt: Are all the arches at Arches National Park open to visitors to walk over? Was the Wall Arch open to visitors before the collapse to hike over? The geology of this special place amazes me with all of its beautiful and unique features carved in eons.

Off the top of my head, I can't think of any arch in the park you can "walk over." Under and past, yes in many cases, but the NPS frowns on you walking over them.

Landscape Arch you can't even stand under due in large part to its fragile nature. You can walk along fins, which are some of the building blocks of arches. In general, if a named arch can be found on a USGS topo map, park regulations prohibit you from climbing onto it.

I'm glad I visited and walked this trail when I had a chance to back in 2001. This is the second great american landmark to become a mere memory that I have had the privilege to see firsthand. The first was Cinder Cone and its associated lava flow in Lassen Park California, which I visited for the first time in 1980. It had such spectacular features as the lava field, which up close looked like water waves frozen in mid crash. You couldn't walk on it or you'd be cut to ribbons. The cinder cone itself featured a perfectly 200' cylindrical hole in the middle that bottomed out in some similarly frozen lava. 20 years later the cinder cone had collapsed in on itself and the hole was a mere 20' feet deep. The lava field was a mere shadow of its former crystaline self with trees growing throughout; it was beginning to blend in with the background landscape. Since it had been there since the mid 1800's, I couldn't believe the amount of erosion that had taken place in the last 20 years, a sure sign of how "global warming" has accelerated the erosive forces for that hitherto slow-changing landscape. I presume that the change in level of rain and snowfall was the primary culprit.

And don't forget the collapse of the Old man of the Mountain in New Hampshire

Another culprit would have been Time - many millions of years of it...

My thoughts exactly...I could see some misguided nuts wanting to put re-bar in all the arches so they don't move. This is nature at its finest.

The forces of wind, water, temperature and time are not to be denied. Erosion giveth, and eventually erosion taketh away. Mother Nature functions both as master sculptor and over time, when she decides she's seen enough and her work has served its purpose, she trades hats and becomes demolition crew. You go Girl!

Just a gentle reminder that, as much as we like to see to the contrary and believe that things as we see them are the way that they are, were and will be, the planet is actually never quite the same at any two moments in time. The careful observer will AWAYS notice minute evolutionary modifications in the environment, from day to day and sometimes from hour to hour, as Nature's job description does not include the term "stagnant".

For what it's worth, you can walk around, through and lean against most of the arches in Arches. Some fools I've seen have tried (a couple actually succeeded) in scrambling up to the zenith of Delicate and Double Arch. Be advised that if you are seen by or reported to the authorities, you are subject to arrest, fines and most unceremoniously escorted from the park. And no, refunds are not included. Revocation of passes is, though.
As it should be.

When I heard of a collapse at Arches, I freaked out! I'm going there soon! I'm sooooo glad it's not the delicate arch. Whew

I just was at Arches last week with my wife. It's a great place. We hiked to Landscape arch, but were out of time, so we didn't make it to Wall Arch.
Make sure you take the ranger guided Fiery Furnace tour if you go. You get to see perhaps the coolest part of the park with narrow fins in a maze-like formation. It was our favorite part of our stop there

Saw the Wall Arch and hiked the trail last year which was a little tricky; but worthwhile. It is very fortunate that no one was injured when the Wall Arch collapsed. Glad we got great photos of it.

Last year was my first time seeing quite a few National Parks (Wow!) now that I'm a retired senior. As far as walking across an arch, in our travels we did see a European tourist walk across one of the arches in Canyonlands merrily taking pictures like it was Disneyland. I couldn't look. I thought he was a gonner. This is the arch that goes across the steep wall at the top of Canyonlands. He was nuts! I got dizzy just looking over the pile of rocks at the base of the arch to see the canyon. He obviously never heard that you can easily have vertigo set in when you are at heights. Plus you should respect our National Parks and climb only in designated areas.


After visiting the red rocks of Arizona and Utah for five summers, I hate to see this happen! Red rocks are unbelieveable. Just a note, I just retuned from Alaska.....the same thing is happening to the glaciers...makes you wonder about Global Warming!

This is the second geologic incident since my recent visit to the SW of Colorado, Utah and Arizona, first was the massive rock slide in the Black Canyon of the Gunnison a short 8 weeks or so ago and now this...! It proves the world is a dynamic place and changes, even ones that normally occur on geologic time scales of millions of years, can and do occur, in an instant. I am privledged to have experienced these wonders prior to their falls and hope many will appreciate the fragility of most of our natural wonders, get out there and experience nature's grandeur knowing nothing is forever.

It was interesting how the collapse of Wall Arch was first reported by the Associated Press. The headline on the Grand Junction Daily Sentinel's Web site read that an "iconic" arch fell at Arches NP. Then, as a Google search of "Landscape Arch" will reveal, the story reported that Wall Arch was the first arch in the park to fall since Landscape Arch fell in 1991. If Landscape Arch had fallen, then the headline would have been justified in proclaiming that something "iconic" had indeed succumbed to the elements. However, Landscape Arch remains intact, albeit precariously, despite that a chunk of sandstone fell from the arch at about that time. Wall arch was quite a spectacle of nature, but it was hardly "iconic." That honor can go to both Delicate and Landscape arches, certainly the most exemplary specimens of their kind found anywhere in Arches National Park or the Colorado Plateau, for that matter.

For the record, the tops of some arches in the park are accessible, but I think it goes without saying that standing on natural arches is not only dangerous and inadvisable, but also potentially damaging to the arches themselves and offensive to visitors who prefer to see sandstone arches in their natural state. Fortunately, after more than 50 visits to Arches National Park in the last decade, I've never once seen anybody stand atop an arch.

This is not at all a sure sign of anything other than the normal erosion that is well known at Arches National Park. If you paid attention during your 2001 trip you would have learned that lots of features of the park have bit the dust literally over the years. There are plenty of before and after photos to show that. In fact, everyone should do their friends a favor and tell them to visit Arches soon, considering the condition of the landscape and delicate arches! I would not be surprised to hear of either of those collapsing in my lifetime.

There is one park in the system where you are allowed, and are encouraged to, walk atop some sandstone arches - Big South Fork National River and Recreation Area, on the Tennessee/Kentucky line. It is 7/10ths of a mile to Twin Arches in the western side of the park via the aptly named Twin Arches Loop Trail. These magnificent structures stand approx. 100 feet long and 70 feet tall. The trail passes beneath as well as on the arches, and continues on past Charit Creek Lodge, historic homesteads, massive blufflines, and other features for one of the South's best easy dayhikes. Big South Fork NRRA is home to one of the largest collections (if not the largest) of rock arches outside of Arches NP. Learn more at and

This was not a funtion of global warming. Nor were the formation of the Arch itself due to global warming. Time and mother nature took it's normal course of action.

except for the fact that cinder cone has only been in existance since the mid 1800's! I witnessed the vast changes since I last visited in the 1980's. It had eroded more in the last 20 years than in the previous 130. What has happened to reading comprehension inis younger generation?

Check out the Natural Arch and Bridge Society, which names Landscape Arch as the longest natural rock span on earth. Now that's "iconic."

Actually, the largest concentration of natural arches in the United States outside of Arches National Park are the Rattlesnake Arches in Colorado's McInnis Canyons National Conservation Area and the Black Ridge Canyons Wilderness, not far from Arches NP. Find more info here:

Rattlesnake Canyon is truly a sight to behold, and quite a hike from nearby Fruita, Colorado -- 16 miles roundtrip if you choose the low trailhead. The high trailhead is only accessible via 4wd vehicle.

Global warming is what created most of our NP's anyway...Love the warming,,,

I am so glad I got to see this arch this year!! It was well at the others being just as wonderful. On some one could tell that it won't be long before the succumb to gravity....see them while you can.


Thanks for correcting me. This is particularly useful information for me to have since I volunteer and sometimes give interpretive programs at BISO.

This arch has been sitting around for half a million years or so without falling. Of course the long term cause is gradual erosion, but I suspect the immediate cause was weather and tide related: drier than normal, coupled with shear stresses caused by a temperature gradient. Problem is, August 1 had a 40 degree differential compared to a 25 degree drop Monday night, and the new moon occurred 2 days earlier as well. The winds were stronger Friday than Monday night. Did it fall two days after it cracked? I doubt it, but there must have been some reason it fell when it did. We're a month past aphelion, with its weaker tides, but the arch has gone through the worst of a summer full of expansion and contraction. Winter freezing and thawing does the long term damage, but summer probably provides more triggering mechanisms. Ice ages may set the arches up to tumble during interstadials. I think natural global warming could be the culprit. --AGF

Maybe it was only by rare chance that my husband and I--visiting Arches in May--saw a couple on top of Wall Arch. Later in the day we saw a man on top of Sand Dune Arch. The following day we saw a woman and her young daughter walk during 30 MPH wind gusts across Mesa Arch in Canyonlands, which is exposed on both sides to tremendous drop offs, so frightening to see that I had to walk away. I was so sure we were about to witness people dying that my experience was wrecked.

Or perhaps these incidents were not coincidental to our visit. Perhaps others blogging here--and park officials, even-- are naive about the audacity of visitors and the frequency with which they stand and walk on top of these fragile, beautiful arches, ignorant or inconsiderate of the harm they do. If there are rules, we saw none posted. If there are not rules and fines--heavy, steep fines--then perhaps there should be.

OK, here's a tenuously proposed triggering mechanism: the humidity was rising that night, and sandstone constitutes a semipermeable membrane. H2O molecules are lighter than N2 and O2, vibrate more rapidly, and find their way through the rock faster than dry air. This enables the rock to build up a partial pressure of water vapor faster than the total pressure of dry air in the rock can be dissipated, so that the gasseous pressure in the rock may build up a few mmHg of pressure--maybe enough to trigger a collapse. I suppose the mechanics and magnitude of such a phenomenon could be studied experimentally. --AGF

Two witnesses to the collapse have come forward.

AGF - I like to think that a canyon raven, a crafty bird in all environments, landed atop the arch thus providing the last few ounces of downward stress causing this immense collapse. Amidst the din and dust the raven was surprised as his footing disappeared. No problem his black wings spread, caught the breeze, and lifted him into the blue sky. Another day in slickrock country.

I recant. But it will be a few days before that raven sets down on another arch in slickrock country. --AGF

Wow, this is two McInnis Canyons NCA references on NPT in about a week - that's got to be a record! Here is one of the more notable arches in the Rattlesnake Canyon area, folks climb through it though it is not an official BLM trail.

Cedar Tree Arch from a distance, McInnis Canyons National Conservation Area

Some more photos of the Rattlesnake Arches area of McInnis Canyons National Conservation Area are located here:

Their are many arches in Arches National Park that you can walk under and a few that you actually can walk on.
It is amazing that no one was hurt when this arch fell.
The Park service needs to have engineers study the arches that are accessible to insure their safety.

This park is one of the most beautiful areas in the United States.

PS It didn't take eons to form the arches. Arches are formed all over the world over a few centuries of wind, flfash flooding rain and weathering.

The entire Colorado Basin is eroding at about the rate Lake Powell is filling up with mud, or formerly, at the rate the Bay of California was filling up--slower than Baja is pulling away. Sandstone buildings erode less than an inch per century. Rainbow Bridge had a stream that flowed around it till the hole broke through; then the stream flowed through the hole, so a narrower gulch formed within a wider gulch. Both gulches help to give us an idea of the Bridge's erosion rates. The rocks that have broken off over the tens or hundreds of thousands of years have turned back to sand, and washed into the sea. It's a pretty slow process. --AGF

I wanted to do that Fiery Furnace walk but was too chicken when they showed me the pics of it. Was it scary or fantastically worth it? I love that park so much. Wish I were there right now for the Perseid.

As I recall there are signs and postings notifying visitors to not walk on any of the arches. Unfortunately many park visitors ignore these postings or just don't care. Most of the offenders aren't even American(from my experience) and in places where there are fines, its not steep enough. On a recent trip through Capital Reef NP there were signs posted with $100 fines for walking off the trail. Whos that gonna scare??

Come on guys, I know its nearly impossible to catch these offenders but when you do...MAKE IT HURT!! We need to send a message to people that it is NOT acceptable to trample wherever in these places.

I am so glad that the Black Canyon and therefore the Curecanti Recreation Area made your list of places to visit!(coming all the way from Australia).
I have a great digital photo of my brother under The Wall Arch from a few years back. What a beautiful hike.
I am glad Arches is protected land as there are so many incredible places nearby that are up of 'the oil shale grab'.

Why can't we just shoot them? Guns are legal in National parks.

I was at Landscape Arch on Monday around 1:00 pm. I can confirm that it was bloody hot. My other family members made us turn back rather than continuing the final 1/4 mile to Wall arch. I'm sorry now that I didn't push them around the next bend of the trail. We also had some rain that evening where we were, near 4 corners. I would support the theory that the week of hot weather followed by a rapid cooling and maybe a bit of rain as the straw that broke the arches back :-)

We stayed in the Devil's Campground the night of the collapse. During the night I thought I heard thunder. But it never happened again. Then early that morning, my family and I hiked the Devils Garden Trail (in 107 degree heat!) and came upon the collapsed Wall Arch. At this point in the morning, park rangers were only just being alerted to the collapse. We took lots of pictures and continued to view the rest of the arches on that trail. Amazing!!! Arches is my favorite NP. So Far....!!!!!

I ca't get enough of Arches - since childhood over 50 years ago - and it personally offends me to see people scurry up the Double Arch area as if by climbing these landmarks they nhave somehow mastered arrogant and impolite to our Mother.

I was there just a few weeks ago. I feel immensely privileged to have been one of the last people to view Wall Arch. It all seems so majestic and immovable when you are there, strange to think that just a few weeks later (a heartbeat in geological time) it's gone.

I just got back from a cross country road trip where we stopped at Arches. We were there about a week before the Wall Arch collapsed. I was blown away when I heard it collapsed because I, like many of you are probably thinking, "I was just there and it looked fine!" What's really scary to me is the fact that I took some pictures sitting under the arch and for those of you into geology, 2 weeks is like a fraction of a second in geology time. Just to think that I could have collapsed when I was there...

What else is very interesting is the size of the Wall Arch compared to others like Landscape. Wall Arch looked so much thicker at the top compared to Landscape. Landscape is so long and thin, I would have though that would have collapsed years, if not decades before Wall.

We just returned from a Utah vacation, which included a trip to Wall Arch. We originally saw it in 2006 and never gave any thought to it collapsing in our lifetimes. Surprising that other seemingly more fragile arches are still standing, and this one fell. A reminder that you can’t always tell the substance of things or people by looking on the outside.

A few folks asked about climbing on arches above...

There is certainly not a blanket law against climbing on all the arches in Arches NP. My family and I went canyoneering with a guide in the Fiery Furnace with full permission of the NPS and we climbed over and then rappelled off of an arch in there. Also, people (myself included) very routinely climb on top of Double O arch near the end of the Devil's Garden trail. I'm very conscientious about not walking on the cryptobiotic soil and obeying "stay on trail" signs and did not see any signs nor trample any sensitive areas when my son and I scrambled up onto Double O from the backside.

That said, it is not permitted to climb Landscape or Delicate arches.

Hey, folks - call and write today to stop the oil lease fire-sale outside Arches and Canyonlands! Call the BLM office in Moab at 435 259 2100. You have until 12/4 to express your outrage.

I was there on Nov 3rd 2006. Have a great photo, different angle but same pine tree background. This fell almost 2 years later. The Old man in the Mountain in White Mtns NH, Franconia Notch fell 24 months after my visit in May 2001. It fell in May 2003. In Yosemite's Curry Village a large granite slab sheared off above Curry Village about two years after my first visit and again recently also two years after my last visit. Wierd how 3 places I've been have fallen after I see them.

Fortunately it fell naturally, not due to some idiot, like that artist who set fire under one of them.

You can look at them, but you can't WALK OVER any of them!!

Just because there is a rule that says you can't do something it doesn't stop the people trying to. If you think you can't walk over an arch take a look at this.

Tried to report it but they were long gone.

@ anon: Your pic shows Mesa Arch in Canyonlands NP and there it is legal to walk over it. It might not be smart, but it is legal. Only Arches NP it is forbidden to climb or walk over any named rock formation including the arches.

I have pictures of my daughter and I under this arch, from july '07, before the falling of it. I'm so glad we were able to see Wall arch before this happened. It was a really cool arch. Arches N.P. is an awesome place to go. Words just just can't discribe the awesome views and just the feeling of hiking to these arches to get up close and personal with them. I can't wait to go again.

I hiked through Wall Arch in 2001. I stopped under each arch I visited and looked up wondering when that split second would happen. I missed it by about eight years.

I hiked to a lot of the arches, and I never saw anybody on top of any of them. But people are, as a general rule, stupid. "Because it's there" mentality will always overcome good judgement.

The one thing missing from Arches is a sign at the entrance to the park. How am I supposed to get my motorcycle poser shot with no sign?

Could somebody mention something to them for me? Thanks.