Is there earthquake risk in St. George, Utah?

St. George has real earthquake risk: the Utah Geological Survey says faults in the St. George–Hurricane area can produce earthquakes as large as magnitude 6.5 to 7. Large ones are rare here, and moderate ones are not. The most recent reminder was the magnitude 5.8 St. George earthquake of September 2, 1992, which is still the event locals mean when they say “the earthquake.”

That is not a reason to avoid buying in Washington County. It is a reason to know which faults are near the house, to understand how earthquake risk here differs from the Wasatch Front, and to make a deliberate choice about insurance rather than discovering the gap afterward.

The 1992 St. George earthquake

At 4:26 a.m. on Wednesday, September 2, 1992, a magnitude 5.8 earthquake struck with its epicenter in Washington Fields, east of St. George (University of Utah Seismograph Stations; Utah Geological Survey Special Study 127, 2008; both checked October 2026). Seismologists have tentatively assigned it to the Hurricane fault.

What it did:

• Springdale. The earthquake triggered a large landslide near Springdale, at the mouth of Zion National Park, that destroyed three houses and a water tank and closed State Route 9. The UGS puts the slide 27 miles from the epicenter, an unusually long distance for an earthquake that size to trigger one.
• Hurricane and Toquerville. Bookcases toppled and goods fell from store shelves in Hurricane, and a historic house there had extensive structural damage. In Toquerville a boulder rolled downhill into a building and at least two cars.
• St. George. Damage was minor: loosened plaster and small wall cracks (University of Utah Seismograph Stations).
• The Virgin River. Saturated river sands liquefied from about a mile south of Bloomington to about four miles west of Hurricane, producing lateral spreads and sand boils. No damage from the liquefaction was reported.

No deaths or serious injuries were reported. The UGS treats 1992 as the kind of moderate quake that is more common in southwestern Utah than a large one, and says such quakes are “capable of doing significant property damage” (Special Study 127).

The honest lesson of 1992 is that the worst damage did not happen where the shaking was strongest. It happened on an unstable slope miles away. That pattern matters for buyers.

The faults near St. George

The UGS has identified more than 50 normal faults in the St. George–Hurricane area, and because the region is still being pulled apart, it treats all of them as potentially active until proven otherwise (Special Study 127, 2008).

Fault	What the UGS says	Where it runs
Hurricane fault	155 miles long; the longest in the area; evidence of repeated surface faulting; likely divided into segments that rupture separately	Along the eastern edge of the metro area, through Hurricane and La Verkin toward Cedar City
Washington fault	42 miles long; trenching in Washington Fields in 2007 found three surface-faulting earthquakes in roughly the last 75,000 years, the latest shortly before about 18,600 years ago	North from Arizona through the Washington Fields area, splitting into smaller faults north of Washington
Other large faults	Warner Valley, Washington Hollow and St. George faults, with hundreds of feet of displacement	Within the basin

Source: Utah Geological Survey Special Study 127, 2008, checked October 2026.

No fault in southwestern Utah has ruptured the surface in recorded history. The geology says large surface-rupturing earthquakes have still happened here in the Holocene, which is geologically recent, and a UGS scientist told the Deseret News in 2007 that the open question on the Hurricane fault is how often they occur (Deseret News, March 18, 2007).

How St. George compares with the Wasatch Front

This is the comparison most people moving south from Salt Lake are actually asking about.

	Wasatch Front	St. George area
Main fault	Wasatch fault, through the most populated valley in the state	Hurricane fault along the east side; Washington fault through Washington Fields
Published forecast	43% chance of a magnitude 6.75 or larger earthquake in the region in 50 years; 57% for magnitude 6.0 or larger	No comparable published probability; the UGS says how often large quakes happen here is not well known
Recent damaging quake	Magnitude 5.7 near Magna, March 18, 2020	Magnitude 5.8, September 2, 1992
Older brick buildings	A large stock of unreinforced masonry, the main concern in state planning	Present in older buildings and neighborhoods; not separately counted in the sources here

Sources: Working Group on Utah Earthquake Probabilities, USGS Fact Sheet 2016-3019; Utah Geological Survey Special Study 127; University of Utah Seismograph Stations; Utah Division of Emergency Management, earthquakes.utah.gov. Checked October 2026.

When the Magna earthquake hit in 2020, the University of Utah Seismograph Stations described it as the largest earthquake in Utah since the 1992 St. George quake. For nearly three decades, the biggest recent shaking in the state had been in Washington County, not on the Wasatch Front.

The fair reading: the Wasatch Front’s risk is better measured and, on what has been published, higher. St. George’s risk is lower on what is known and less well known. “Less studied” is not the same as “safe,” and I would not let anyone talk you into thinking it is.

What tends to cause the damage here

The UGS is plain that most earthquake damage comes from ground shaking, not from a fault breaking the surface under a house. In Washington County a few things raise the stakes on a particular property.

Slopes. 1992’s worst losses were a landslide. A house on or below a hillside, especially on clay-rich rock, carries earthquake risk the flat lots do not. What to check before buying on a hillside applies well beyond La Verkin.

River sands. Liquefaction happened along the Virgin River in 1992. Low ground near the rivers with shallow groundwater is where the UGS maps the higher liquefaction categories.

The soil itself. The same ground that troubles foundations here, expansive clay and collapsible soil, is covered in whether St. George soil is bad for foundations. It is a separate problem from earthquakes, but it is the same reason the geotechnical report on a lot matters.

Unreinforced brick. Unreinforced masonry, brick walls with little or no steel, is the building type most likely to collapse in an earthquake. Utah changed its codes in the 1970s to stop new construction of it, and state emergency managers expect it to account for 75 percent of building losses in a magnitude 7 to 7.5 Wasatch Front quake (earthquakes.utah.gov, Utah Division of Emergency Management). Possible signs: a row of bricks turned endways every five or six rows, deeply recessed windows, and rows of bolt heads or metal rosettes on exterior walls.

What St. George City requires

St. George adopted the UGS and FEMA hazard maps into its code in 2019. For development inside a mapped fault area, which the code defines as 500 feet on the downthrown side and 250 feet on the upthrown side of a well-defined fault, or in a very high liquefaction or landslide area or a high rockfall area, the applicant must submit a site-specific report from a licensed engineering geologist or geotechnical engineer, and the city must accept it before building (St. George City Code 10-13B-2, Ord. 2019-10-002, amended 2020; checked October 2026).

Two parts of that rule are useful to a buyer. The developer has to sign a hold-harmless agreement and place a “notice of hazard” on the final plat, and the reports are identified on the plat and available to owners. So for a newer subdivision in St. George, the recorded plat can tell you whether a hazard study was required and where to find it. Older neighborhoods built before 2019 will not have that trail.

What to check before you buy

• Look up the parcel on the UGS hazard maps. They show fault special-study areas, liquefaction and landslide categories. They are planning maps, not a verdict on one lot.
• Read the plat. Look for a notice of hazard and the name of the geotechnical report.
• Ask for the report itself on new construction, and read what it said about faults, slopes and liquefaction.
• Ask about the build year and the walls on an older home. Brick veneer over a wood frame is common and is not the same thing as unreinforced masonry. An inspector or engineer can tell you which one you have.
• Bring a structural engineer for an older masonry house or anything on a slope. A southern Utah home inspection covers who else is worth adding.

Earthquake insurance

The Utah Insurance Department says earthquakes are generally not covered under a homeowners policy, and earthquake insurance is a separate, supplemental policy (Utah Insurance Department, April 2017). The Utah Geological Survey adds the uncomfortable part: if an earthquake destroys your home and you have no earthquake coverage, you still owe the mortgage. That is the sharpest argument for buying it, and whether earthquake insurance is worth it in Utah works through how the percentage deductible changes the math.

Earthquake deductibles are calculated differently from an ordinary homeowners deductible, and they are often large enough that modest damage is paid out of pocket either way. Ask your agent for a written quote, how the deductible is calculated, and what it comes to in dollars on this house before you decide. Flood is a separate exclusion again; whether you need flood insurance in Washington County covers that one.

I tell clients to make the earthquake insurance decision on purpose, during due diligence, with a real quote in hand. Most people never decide at all, which is the same as deciding no.

I am Kelsey Earl, a Realtor with Keller Williams South Valley, and if you are weighing St. George against staying on the Wasatch Front, this is where I would start.

Note: General information drawn from published geologic studies and agency guidance, not engineering, insurance or legal advice. Hazard maps are for planning; only a licensed engineer who has examined a specific property can assess it, and only your insurer can tell you what your policy covers.