Earthquakes risk in Wyoming

If you're buying a house in Jackson or Pinedale, your inspector will check the roof, the furnace, the foundation — but they won't tell you how the ground moves. That's on you. Wyoming isn't California, but it's not flat and quiet either.

Why Wyoming looks like this

Wyoming sits on the Intermountain Seismic Belt, a band of faults that runs from Montana through Yellowstone and down into Utah. The Teton fault, just west of Jackson Hole, is one of the most active in the lower 48. It can produce large earthquakes. Yellowstone National Park records hundreds to thousands of tiny quakes most years. That's not a reason to panic, but it is a reason to pay attention.

The western part of the state feels it most. Teton County, Sublette County, Lincoln County, and Uinta County have the highest shaking potential. The Wind River Range, the Bighorn Basin, and the Absaroka Range all have faults. Even Cheyenne and Casper, farther east, can feel shaking from time to time. In 1959, the Hebgen Lake earthquake just over the Montana line near West Yellowstone caused damage in Wyoming. It was a reminder that this region can move.

What actually happens to a house? Most Wyoming homes are wood-frame, which flexes better than brick or stone. But chimneys crack. Foundations shift. Unsecured water heaters tip and break gas lines. Bookshelves fall. Windows shatter. A moderate quake — say magnitude 5 or 6 — can crack drywall and knock things off walls. A larger one on the Teton fault could do serious damage in Jackson, Wilson, and Moose. The risk is real but localized.

Insurance gaps people miss

Here's the part that surprises people: your standard homeowners policy does not cover earthquake damage. It's excluded. You have to buy a separate earthquake policy or add an endorsement. In Wyoming, that's available from many insurers, but it's not cheap. Deductibles are often 10% to 15% of your dwelling coverage. On a $400,000 house, that's $40,000 to $60,000 out of pocket before insurance pays a dime.

Flood is also excluded from standard policies. You'd need a separate NFIP policy or private flood insurance. And here's a split people mix up: earthquake shaking is not flood. If an earthquake causes a landslide or a broken pipe floods your basement, your earthquake policy might cover the shake damage but not the water. You need to read the fine print.

If you live in Teton County or along the western edge, call your insurance agent and ask three questions: Do you offer earthquake coverage? What's the deductible? Does it cover masonry and chimneys? If you can't get a straight answer, shop around. In many mountain counties, insurers are picky about older homes with unreinforced foundations.

A practical weekend plan

If you do nothing else, do this: anchor your water heater to the wall studs with metal straps, and know where your gas shutoff valve is. Those two steps take an afternoon and can prevent a fire after a quake. Then secure tall bookshelves and cabinets to studs. Move heavy items to lower shelves. Put a wrench near the gas meter.

Next, walk your foundation. Look for cracks that are wider than a pencil, especially at corners. If you see them, hire a structural engineer. In older homes around Lander, Riverton, or Cody, unreinforced brick chimneys are a common weak point. Bracing them or replacing them with a framed chimney is worth the money.

Finally, practice drop, cover, and hold on. Ready.gov has a simple guide. If you're in bed, stay there and cover your head with a pillow. If you're outside, get away from buildings and power lines. If you're driving, pull over and set the parking brake. Don't run outside during the shaking — that's when most injuries happen.

Questions we get

Does Wyoming really have earthquakes?

Yes. The western part of the state is one of the most seismically active areas in the lower 48. Yellowstone alone sees hundreds to thousands of small quakes each year, and the Teton fault is capable of magnitude 7 or larger. Most of those quakes are too small to feel, but the risk is there.

Is earthquake insurance worth it in Wyoming?

It depends on where you live and what your house is made of. If you're in Teton, Sublette, Lincoln, or Uinta County, and your home has a masonry chimney or an older foundation, it's worth pricing out. If you're in Cheyenne or Casper, the risk is lower, but a policy can still be cheap peace of mind. Get a quote and compare the deductible to what you could afford to pay out of pocket.

What should I do first if I'm buying a house in Wyoming?

Ask your inspector to look for earthquake weaknesses: foundation cracks, unbraced chimneys, water heaters without straps. Then check the USGS fault maps for your address. If you're near the Teton fault or in the Yellowstone region, factor earthquake insurance into your closing costs. Don't assume your regular policy has you covered — it doesn't.

Official maps and agencies

Here are the sources we trust for Wyoming earthquake information. Start with the state office for local guidance, then use USGS for maps and real-time data.

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

That's the short version. Wyoming's earthquake risk is moderate, but it's not zero. If you're in the western counties, treat it like you would a wildfire or a blizzard — something to prepare for, not fear. And if you only do one thing this weekend, strap your water heater. It's cheap, it's easy, and it matters.