Is there an explanation for recent rockfalls in Utah?

Jun 2, 2022, 6:40 PM | Updated: 9:17 pm

CEDAR HILLS, Utah — A hiker is in the hospital after a rock the size of a tennis ball hit her on the Timpanogos Cave Trail.

It happened around 7:15 a.m. Thursday, according to Sgt. Spencer Cannon of Utah County Sheriff’s Office. Cannon said the rock knocked the 65-year-old woman unconscious and caused bleeding from her head.

Search and rescue crews carried her off the mountain to a waiting helicopter that flew her to a hospital

This is the third rock fall in Utah in the past few days, the most notable being a massive slide captured at Lake Powell on Memorial Day near the entrance to Warm Creek.

Steve Carter captured the video as the slide sent debris and water shooting into the air.

WATCH: Video captures massive rock collapse at Lake Powell

On June 1, a rockslide closed Mt. Carmel Highway in Zion National Park. After initially clearing the road, the National Park Service staff observed other loose rocks above the road and used a water pump from a fire truck to dislodge them.


While the incidents were in different parts of the state and were different sizes, they did have one thing in common.

“We did have a big rainfall event over most of the state over Memorial Day weekend so that may be some of what we’re seeing it,” said Rich Giraud, a Senior Geologist with the Utah Geological Survey.

Giraud said rock falls in Utah are sporadic, especially those with injuries. In fact, since 1874 there have been 15 deaths due to rockfalls.

Utah rockfall fatalities since 1850, based on newspaper, reports, and scientific descriptions of events. (Utah Geologic Survey)

“One of the best ways to think about rock fall is they’re very random and they’re very sporadic, but a rock that is on a cliff is continually being conditioned to pop off. Each freeze-thaw, each hot-cold, each rainfall conditions that rock,” he said.

For those who like to recreate in our various Utah landscapes, there are ways to be educated about potential rockfall hazard areas.

Giraud said you can protect yourself by looking for any debris that is already on the ground. “If you’re below a cliff and there is fresh rock on the ground, be aware that a rock fall can happen there and you don’t want to linger or spend too much time there.”

For those who frequent the Lake Powell area, a good resource to keep on hand is the Geological Hazard Report for the high-use areas of Glen Canyon National Monument and Lake Powell. The report lists areas geologists are studying and could be dangerous.

“This is good for people who visit Lake Powell and understanding how to manage your risk on the lake, where you beach your boat, where you camp, where you hike.”

Giraud said the drop in the water level at Lake Powell could also contribute to more rockfalls in the coming years and warned visitors to be cautious. He said pressure in the rock changes with the lack of water.

“When you get the sudden drawdowns, then the changes are more rapid. If it’s slow, it’s not quite as rapid,” he explained.

Geological Hazard Report for the high-use areas of Glen Canyon National Monument and Lake Powell: ss-166.pdf (utah.gov)

KSL 5 TV Live

Top Stories

Outdoors & Adventure

Enjoying the outdoors can take special skills, but a new program hopes to educate more Utahns so th...
Karah Brackin

‘Becoming Outdoor Women’ aims to empower Utah women with outdoor skills

Through “Becoming Outdoor Women,” a nonprofit educational program new to the state, the goal is for Utah women to develop confidence in those skills and, in turn, themselves.
3 days ago
Tuffy (the dog) gazing up at the Milky Way over Metate Arch in Grand Staircase-Escalante National M...
Brooke Williams

Free-entry to all national parks and monuments Saturday

National Parks free entry on September 24.
9 days ago
Follow @KSL_AlexCabrero...
Alex Cabrero

Hanksville looking ahead to growth 1 year after devastating flash floods

It started with a simple idea: Why not live and work where you love?
29 days ago
There are five kinds of rattlesnakes that populate Utah (DWR)...
Shara Park and Larry D. Curtis, KSL TV

Utahns experiencing close encounters of the rattlesnake kind

As you make plans to head to the great outdoors this holiday weekend, you may want to heed the warning about rattlesnakes.
3 months ago
FILE: The sun sets over Canyonlands National Park. (Ken Fall)...
JOHN FLESHER AP Environmental Writer

Federal agencies reverse Trump limits on habitat protection in Endangered Species Act

The Biden administration is dropping a rule adopted under former President Donald Trump that limited which lands and waters could be designated as critical habitat for imperiled animals and plants.
3 months ago
red flag warning Utah...
Larry D. Curtis

Fire, wind and heat warnings issued for much of Utah

At temperatures jumped significantly from Wednesday to Thursday, much of the state is under warnings for high wind, excessive heat and high fire danger.
4 months ago

Sponsored Articles

Happy diverse college or university students are having fun on their graduation day...
BYU MBA at the Marriott School of Business

How to choose what MBA program is right for you: Ask these questions before you apply!

Wondering what MBA program is right for you? Take this quiz before you apply to see if it will help you meet your goals.
Cloud storage technology with 3d rendering drawer with files in cloud...
PC Laptops

How backing up your computer can help you relieve stress

Don't wait for something bad to happen before backing up your computer. Learn how to protect your data before disaster strikes.
young woman with stickers on laptop computer...
Les Olson

7 ways print marketing materials can boost your business

Custom print marketing materials are a great way to leave an impression on clients or customers. Read for a few ideas to spread the word about your product or company.
young woman throwing clothes to organize a walk in closet...
Lighting Design

How to organize your walk-in closet | 7 easy tips to streamline your storage today

Read our tips to learn how to organize your walk-in closet for more storage space. These seven easy tips can help you get the most out of your space.
Types of Computer Malware and Examples...
PC Laptops

5 Nasty Types of Computer Malware and Examples | Everything You Need to Know to Keep Your Computer and Family Safe

Here are the different types of computer malware and examples that could potentially infect your computer.
tips how to quit smoking...

7 Tips How to Quit Smoking | Quitting Smoking Might be One of the Hardest Things You Ever Do but Here’s Where You Can Start

Quitting smoking cigarettes can be incredibly difficult. Here are 7 tips how to quit smoking to help you on your quitting journey.
Is there an explanation for recent rockfalls in Utah?