Natural Disasters in Montana: What Is the Risk?

Over 1 million people live in Montana. Many of these people have experienced natural disasters in the state firsthand or had to evacuate because of disasters. However, many Montanans don’t realize just how many types of natural disasters can occur in the state.

This analysis covers what natural disasters occur in Montana, the worst natural disasters to hit the state since 2000, and what residents can do to prepare.

Is Montana At Risk of Natural Disasters?

Montana has a medium risk of natural disasters compared to the rest of the United States. Excluding COVID, Montana has had 70 disaster declarations since 2000. Of these, 20 were declared major disasters. 

Montana is also sometimes hit by natural disasters, which cause more than $1 billion in damages. Since 2000, more than 26 separate $1-billion events have affected the state. Most of these were wildfires.

Worst Natural Disasters in Montana By Cost (Since 2000)

1. 2012 Drought and Heat Wave: $39.3 billion
2. Summer-Fall 2018 Wildfires: $28.3 billion
3. 2022 Drought and Heat Wave: $22.2 billion
4. Summer-Fall 2017 Wildfires: $22 billion
5. Fall 2020 Wildfires: $18.9 billion

Worst Natural Disasters in Montana By Deaths (Since 2000)

1. 2021 Drought and Heat Wave: 229 deaths
2. Spring-Fall 2000 Drought and Heat Wave: 140 deaths
3. 2022 Drought and Heat Wave: 136 deaths
4. 2012 Drought and Heat Wave: 123 deaths
5. Summer-Fall 2018 Wildfires: 106 deaths

*Cost and death tolls are for the entire disaster, including in other states affected.

Most Common Natural Disasters in Montana

1. Wildfires

Montana is one of the top 10 riskiest states for wildfires, for both number of fires and acres burned. The western part of the state is particularly high-risk, but no areas of Montana are immune. 

Since 2000, Montana has been affected by 13 billion-dollar wildfires and has had to declare disaster because of wildfire more than 50 times.

Because of climate change, the risk of wildfires in Montana is growing. By 2050, an estimated 93% of all properties will be at risk of wildfires.

Which Areas of Montana Are Most At-Risk for Wildfires?

More than 137,000 properties in Montana – or 29% of all properties in the state — are at high or extreme risk of wildfires. Another 25% are at moderate risk of wildfires.

Even areas that are not at risk can still be affected by wildfires, such as bad air quality, road closures, and economic losses. For this reason, it is incredibly important that all Montanans have a wildfire Go Bag prepared.

Counties most at risk for wildfires in Montana:

• Mineral
• Lincoln
• Granite
• Silver Bow
• Deer Lodge

Largest Wildfire in Montana History

The Valley Complex wildfire in 2000 was the largest the state has seen in terms of acres burned.   By the time the fire was extinguished, it had consumed 292,100 acres in the Montana.

2. Earthquakes

Montana, particularly the western part of the state, is at very high-risk for earthquakes. The state has approximately 7 to 10 earthquakes daily, making it the 4th most seismically-active state in the country.

Most of these earthquakes are too small to feel. However, Montana has the potential for large, destructive earthquakes: it’s ranked #8 in the USA for the greatest magnitude quake achieved yearly. 

Which Fault Lines are in Montana?

Montana has many active fault lines running through it. Most of these are located in the Intermountain Seismic Belt. This belt extends from the Flathead Lake region in the northwest of Montana through the Yellowstone region along the borders of Idaho and Wyoming. 

This belt was responsible for the Hebgen Lake earthquake in 1959. It had a magnitude of 7.5, making it one the strongest earthquakes ever in the continental USA.

In addition to these tectonic earthquakes, Montana also has earthquakes from volcanism. As plates move over volcanic hot spots, such as those found in the Yellowstone area, the earth’s lithosphere can bend and trigger earthquakes. 

3. Snow Storms and Winter Weather

Montana ranks #16 in the country for the most snowfall and most snowfall days per year.   However, this average is a bit deceptive because it looks at the state as a whole. The south-central part of Montana averages nearly 130 inches of snowfall per year.

Snowfall in Montana often comes in the form of snow storms or blizzards. These storms can cause power outages, burst pipes, dangerous road conditions, and business closures. 

Because Montana is so sparsely populated, it can take longer to clear roads.   This results in dangerous driving conditions. With 11.3 fatal crashes per 1 million drivers, Montana ranks #6 in the country for fatal winter vehicle accidents.

4. Flooding

Montana is one of the most at-risk states for flooding in the country. More than 14% of all properties in Montana are at substantial risk for flood disasters. Flooding usually occurs in the spring when snowmelt and heavy rains cause rivers and streams to overflow.  

Flash floods are also common in Montana. The state is often under drought conditions and has many wildfires. When rain hits the dry soil or burned areas, it can’t be absorbed fast enough, and flash flooding or debris flows can occur. 

Which Areas of Montana Are Most At-Risk to Flooding?

Floods can occur in all parts of Montana, but some areas of the state are particularly at-risk. Below are the areas of Montana with the greatest percentage of properties likely to experience flooding (based on 2020 calculations). 

• Evergreen: 81%
• Red Lodge: 51%
• Helena Valley West Central: 44%
• Miles City: 40%
• Lewistown: 33%
• Anaconda: 33%
• Four Corners: 32%
• Helena Valley Southeast: 30%
• Missoula: 27%
• Orchard Properties: 26%

In addition to these areas, there are many major cities and towns in Montana where thousands of properties are at risk. This includes over 6,500 properties in Billings and over 3,400 in Great Falls.

Because of climate change, the risk of flooding is increasing in many parts of Montana. By 2050, an estimated 15% of all properties in the state will be at substantial risk of flooding. 

5. Heat Waves and Droughts

Montana doesn’t have many days of what the National Weather Service calls “extreme danger” heat: days where the heat index is 124F. However, that doesn’t mean Montana isn’t at risk of high temperatures. Over the next few decades, the “Local Hot Days” risk in Montana is expected to increase. 

Local Hot Days are defined as “Days at or above the 98th percentile temperature, or the temperature than an area could expect to see on the hottest 7 days of the year.”  Essentially, Local Hot Days factor in what temperatures a local population is used to experiencing.  

Since many people in Montana don’t have air conditioning, increased temperatures – even when they aren’t considered “dangerous” – can have severe implications. Health problems like strokes increase, and heat-related deaths also are more likely to occur. 

All parts of Montana are expected to see more Local Hot Days over the next few decades. However, Beaverhead County is particularly at risk. In 2053, Beaverhead County can expect to see 17 consecutive days of temperatures at or above 84.4℉.

Heat waves are often accompanied by droughts. As an agricultural state, droughts can be particularly devastating for Montana and have a huge economic toll. Droughts also increase the already-high risk of wildfires in Montana.