Earthquakes occur daily in Wyoming but are often not strong enough for humans to feel. The majority of the state’s earthquakes occur in western Wyoming and the Yellowstone region, though earthquakes have been recorded historically in all parts of the state. Geologists study Quaternary faults—those that have been active in the last 2.6 million years—to understand where and when large earthquakes have occurred in the past. Learn more about earthquakes.

Landslides occur every year in Wyoming, typically in the spring. Though the majority happen in remote, mountainous locations and have little impact on humans, those that occur near populated areas or along transportation corridors can cause major losses to infrastructure and result in millions of dollars in damage. Learn more about landslides.

Radon is a radioactive gas that comes from the natural decay of uranium and can be released into the air from rock, soil, and groundwater. It can build up in dangerous concentrations in enclosed spaces and is the second leading cause of lung cancer in the United States. Radon is one of Wyoming’s most widespread geologic hazards, with elevated levels documented in all 23 counties. Learn more about radon.  

Volcanic eruptions can produce a variety of geologic hazards, including airborne debris, earthquakes, hot gasses, landslides, and hydrothermal explosions. Over the last 2.1 million years, three caldera-forming eruptions associated with the Yellowstone volcanic system have covered vast areas of North America with ash. The last of these major eruptions occurred 631,000 years ago and created the present-day Yellowstone caldera. However, most volcanic eruptions in Yellowstone are not catastrophic events, and there have been around 80 smaller lava flows since the last caldera-forming eruption. Learn more about the Yellowstone volcanic system.

Expansive soils shrink and swell when subjected to changes in moisture. Highways, structures, and utility lines are susceptible to damage from expansive soils, resulting in maintenance and repair costs. Learn more about expansive soils.

Windblown deposits form when sand, silt, or clay particles are transported by wind and deposited on the ground surface. These deposits can cover roadways and agricultural lands and encroach on structures. Vegetated windblown deposits are generally more stable, but they may become active again if they are disturbed and not properly re-vegetated or stabilized. Learn more about windblown deposits.