Earthquakes risk in Wyoming

Earthquake Risk in Wyoming: What Homeowners Should Know

Wyoming is rated level 3 out of 5 for earthquake risk by FEMA's National Risk Index, meaning the state faces a relatively moderate chance of damaging shaking compared to the rest of the United States. The primary driver of this risk is the Yellowstone volcanic system and its associated fault zones, which produce frequent small earthquakes and occasional larger swarms.

The USGS Earthquake Hazards Program maps seismic hazards across the country. For Wyoming, the highest hazard areas are in the western part of the state, especially around Yellowstone National Park and the Teton Range. However, earthquakes have been recorded in nearly every corner of Wyoming, including the eastern plains. Unlike floods or tornadoes, earthquakes have no season; they can strike at any hour, day or night.

Most Wyoming earthquakes are too small to feel. The USGS notes that the Yellowstone region regularly experiences earthquake swarms—clusters of small quakes that can last for days or weeks. These events rarely cause damage, but they serve as reminders of the region's tectonic activity. A larger earthquake, though less frequent, is still possible and could affect homes in a wide area.

How Earthquakes Affect Homes in Wyoming

When an earthquake hits, the ground shakes in waves. The severity of damage to a home depends on many factors: distance from the epicenter, local soil conditions, and the construction quality of the house. In Wyoming, the most likely damage from a moderate or severe earthquake includes:

• Foundation movement or cracking – Especially in homes built on steep slopes or soft soils.
• Chimney and masonry damage – Brick chimneys and unreinforced masonry walls are particularly vulnerable to shaking.
• Broken windows and doors – Settlement or twisting of the frame can jam doors and crack glass.
• Falling interior items – Unsecured bookcases, water heaters, and overhead light fixtures can topple or break.
• Utility line ruptures – Gas lines and water pipes can break, creating fire hazards and water damage.

Ground shaking is the primary threat, but in mountainous areas like Jackson Hole, earthquakes can also trigger landslides or rockfalls that affect homes at the base of slopes. Soil liquefaction—where water-saturated ground behaves like a liquid—is less common in Wyoming but possible near rivers and lakes.

Regarding insurance, standard homeowners insurance policies in Wyoming do not cover earthquake damage. To be protected, you must purchase a separate earthquake insurance policy, typically offered as a rider or endorsement. The FEMA Earthquake Safety page explains that earthquake insurance covers repairs to your home, personal property, and sometimes additional living expenses. Wyoming homeowners in western counties—especially Teton and Park—should seriously consider this coverage, given the higher seismic hazard.

How to Prepare Your Home for an Earthquake

Preparing your home can reduce injuries and property loss. The Ready.gov – Earthquakes website recommends taking action before shaking starts. Follow these practical steps:

1. Secure heavy furniture – Anchor tall bookcases, dressers, and televisions to wall studs using straps or brackets.
2. Install latches on cabinets – This prevents dishes and glassware from crashing to the floor.
3. Strap your water heater – A single water heater holding 50 gallons can weigh over 400 pounds and may topple, causing gas or water leaks.
4. Identify safe spots – Under sturdy tables, against interior walls away from windows, and next to low, heavy furniture that can shield you.
5. Know how to shut off utilities – Learn to turn off gas and water at the main valves, and keep tools accessible.
6. Create a family emergency plan – Choose an out-of-state contact and practice Drop, Cover, and Hold On.
7. Build an emergency kit – Include water, food, flashlights, batteries, first-aid supplies, and important documents.
8. Check your foundation – If you live in an older home, consult a structural engineer to see if your foundation is bolted to the frame.

Even simple measures like moving heavy picture frames away from beds and securing your computer monitor can make a difference. Take these steps now, before the next tremor, so you are not scrambling when shaking begins.

Frequently Asked Questions about Earthquakes in Wyoming

Can a large earthquake trigger a Yellowstone eruption?

No. According to the USGS, earthquake activity at Yellowstone is closely monitored, and while earthquakes are common, they do not directly trigger volcanic eruptions. The volcano's status is tracked continuously, and any significant unrest would be detected far in advance. A major earthquake near the park could alter geothermal features, but an eruption is not imminent.

Does my standard homeowners insurance cover earthquake damage?

No. Standard homeowners insurance policies in Wyoming specifically exclude earthquake damage. You must purchase a separate earthquake insurance policy or add an endorsement. Check with your insurance agent to understand your coverage, and consider the cost versus the risk, especially if you live in the western part of the state.

What should I do during an earthquake in Wyoming?

The official recommendation from Ready.gov is to Drop, Cover, and Hold On during an earthquake. Drop to your hands and knees, take cover under a sturdy table or desk, and hold on until the shaking stops. If you are indoors, stay inside—do not run outside. If you are outdoors, move away from buildings and power lines. For more details, visit the Ready.gov earthquake page.

Official Resources for Wyoming Earthquake Preparedness

For more information, consult these authoritative sources:

• Wyoming Office of Homeland Security
• USGS Earthquake Hazards Program
• Ready.gov – Earthquakes
• FEMA Earthquake Safety