Risky Terrain: 2025’s Most Landslide-Vulnerable Counties

Which counties are teetering on the edge of disaster, where homes, boulders, and mud risk tumbling down hillsides?

With landslide season in full swing, Home Gnome ranked 2025’s Most Landslide-Vulnerable Counties.

We compared over 700 of the biggest U.S. counties based on three categories. We looked at landslide, earthquake, and avalanche risk, the net change in tree cover over the last 20 years, and expected annual financial loss from landslides, among 11 total metrics.

Slide into our ranking below. To learn how we ranked the counties, see our methodology.

In This Article

• Quick Stats
• The Leaderboard
• The Most Landslide-Vulnerable Counties
• The Least Landslide-Vulnerable Counties
• Professional Take
• Behind the Ranking
• Rock Solid Defense: Landscape Protection Tips

Quick Stats

• On Shaky Ground: Oregon dominates with 6 counties, including Lincoln County (No. 1) and Douglas County (No. 2), topping the list for the highest landslide risk scores. Pitkin County, Colorado (No. 24) and Elmore County, Idaho (No. 20), bring the Rockies into the mix, while Floyd County, Kentucky (No. 21) faces steep risks in the Appalachian region.
  
• Rain Check: On average, Jefferson County, Washington (No. 601) experiences a staggering 532.3 inches of rain annually but lands safely in the bottom half of the ranking. With over half of the county covered by Olympic National Park and Olympic National Forest, development is limited, keeping expected financial losses to a minimum despite heavy rainfall. On the other side, Tillamook County, Oregon (No. 3), faces high landslide risk with similar soggy conditions.
  
• Unstable Slopes: Multnomah County, Oregon (No. 9), Ventura County, California (No. 75), and San Bernardino County, California (No. 79), face double trouble with high earthquake and landslide risk scores.

The Leaderboard

See how each county fared in our ranking:

The Most Landslide-Vulnerable Counties

• West Coast Woes: The Pacific Northwest dominates the top 25, with Oregon and Washington counties at the greatest risk. Santa Cruz County, California (No. 13) stands out as the only California locale in the top 25, while McDowell County, North Carolina (No. 22) is the lone East Coast contender. All top 25 counties face high landslides and financial risks, making preparedness essential.
  
• Trigger Warning: Harris County, Texas (No. 439) may slide under the radar, barely scraping into the top half of the ranking. But the county’s high Trigger Rank (thanks to hurricanes, drought, wildfires, and flooding) keeps it on shaky ground. With a landslide risk score of 83.23 — in the danger zone — it’s a disaster cocktail waiting to spill, thankfully financial loss is expected to be minimal. 
  
• High-Stakes Slopes: A landslide could cost 20 counties more than just dirt — they all face expected financial loss exceeding $1 million. Oregon leads the pack with 9 counties, followed by Washington with 6. Colorado, Idaho, Kentucky, Ohio, and West Virginia all add 1 county with significant financial risk to the mix. 

The Least Landslide-Vulnerable Counties

• Rock-Solid Rankings: While all counties in the ranking face at least moderate landslide risk, the bottom 25 show more stability, with Midwestern counties like Allamakee County, Iowa (No. 743) and Vernon County, Wisconsin (No. 742) leading the pack. Crook County, Oregon (No. 732) is a surprising addition, thanks to lower annual precipitation and expected financial loss.
  
• Minimal Mudslides: 60 counties face the lowest financial impacts from landslides, each with expected annual losses under $100,000. Wayne County, Tennessee (No. 698) leads with the least expected loss at around $49,000. Despite moderate to high risks, sparsely populated regions like Klickitat County, Washington (No. 682), and San Juan County, Utah (No. 725), benefit from their rugged, undeveloped landscapes, keeping potential damages to a minimum.
  
• Rooted resilience: 9 counties, including Adams County, Colorado (No. 450), and Johnson County, Kansas (No. 681), saw tree cover increase by 15% or more over 20 years, helping to root these counties firmly in the less vulnerable half of the rankings. Broward County, Florida (No. 361), however, increased its tree canopy but still faces higher landslide risks.

Professional Take

Landslides pose a significant threat to communities across the U.S., with an average of 25 to 50 fatalities annually. But how can homeowners better protect themselves and their properties from this natural hazard?

We turned to a panel of experts to learn about the warning signs, preparation strategies, and the impact of climate change on landslide frequency and intensity. Read their insights below.

1. What are the three most important signs that a landslide could be imminent?
2. What are the top three ways to prepare for a landslide?
3. What should victims do immediately after a landslide?
4. How is climate change affecting landslide frequency and intensity?
5. Is it possible for local governments to prevent residential structures from being built in landslide-prone areas? Why or why not?

Aaron Gallant, Ph.D., P.E.

Associate Professor of Geotechnical Engineering

Aaron Gallant, Ph.D., P.E.

Associate Professor of Geotechnical Engineering

University of Maine

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Aaron Gallant, Ph.D., P.E.

Associate Professor of Geotechnical Engineering

University of Maine

What are the three most important signs that a landslide could be imminent?

Ground movements are the most obvious sign that a landslide is imminent. This could manifest as sloughing, settlement, tension cracks due to lateral spreading, or bulging at the toe or base of a slope. If facilities are being supported on unstable ground, ground movements can manifest as distress to the superstructure (e.g. cracking and damage to the facade and interior walls of the structure, settlement, and rotation). Abrupt changes or damage to other landmarks (e.g. trees, fences) could be a sign as well.

What are the top three ways to prepare for a landslide?

It’s important to understand that landslides occur abruptly and can have catastrophic consequences. When a ground failure occurs, there’s little you can do at that point. Thus, the best thing you can do is to avoid areas and ground conditions susceptible to ground failures. Placement of critical infrastructure should avoid risky areas if possible. When it’s not possible, there are means to stabilize ground at risk of instability by incorporating groundwater drainage systems and/or stabilizing via an earth retention system (e.g. retaining wall, ground anchors, soil nails, etc.).

What should victims do immediately after a landslide?

Landslide victims should immediately evacuate the affected area. More instability may follow. It’s also worth considering what may have been destabilized uphill of the landslide, especially if water is involved (e.g. water tank, water reservoir, canal, etc.). Flash flooding is also a possibility. People should attempt to move out of the flowslide footprint (perpendicular to the flow direction and not downhill) to avoid secondary instabilities that could bring more debris or water downhill.

How is climate change affecting landslide frequency and intensity?

Rainfall often triggers landslides. As the frequency and intensity of rainfall events increase, more landslides can be expected. In arctic regions, we have permafrost layers melting, resulting in weaker and softer ground conditions that can lead to ground failures. Though this issue poses a risk to fewer people, it’s something arctic populations will need to combat.

Is it possible for local governments to prevent residential structures from being built in landslide-prone areas? Why or why not?

It’s possible but is driven by the risk tolerance of policymakers and their constituents. Any policy needs to balance the economic consequences associated with limiting the supply of land on which people can build and the population’s safety.

Behind the Ranking

First, we determined the factors (metrics) that are most relevant to rank the Most Landslide-Vulnerable Counties. We then assigned a weight to each factor based on its importance and grouped those factors into 3 categories:

The categories, factors, and their weights are listed in the table below.

For each of the 743 biggest U.S. counties with moderate to very high landslide risk according to the Federal Emergency Management Agency (FEMA), we then gathered data on each factor from the sources listed below the table.

Finally, we calculated scores (out of 100 points) for each county to determine its rank in each factor, each category, and overall. A county’s Overall Score is the average of its scores across all factors and categories. The highest Overall Score ranked “Most Vulnerable” (No. 1) and the lowest “Least Vulnerable” (No. 743).

Sources: FEMA, National Centers for Environmental Information, and Global Forest Watch

Rock Solid Defense: Landscape Protection Tips

Landslides are a deadly force of nature, causing significant property damage and loss of life. Natural hazards like heavy rainfall, wildfires, and earthquakes increase the risk of landslides, making preparation crucial, especially those near slopes or high-risk areas. 

Strategic landscaping, home maintenance, and proper drainage systems can significantly reduce the threat. Read through some essential tips below to help minimize landslide risks and keep your home safe. 

• Know Your Terrain: Research historical landslide activity in your area. They tend to strike the same places.
  
• Stay Alert: Sign up for local emergency alerts, and craft a clear evacuation plan for your household.
  
• Smart Landscaping: Plant trees and ground cover to stabilize soil and prevent erosion, especially on slopes.
  
• Build Defenses: Construct retaining walls or diversion channels to safely direct rainwater away from your property. Be cautious not to redirect water onto neighboring land to avoid liability. 
  
• Fortify Your Home:  Ensure your roof, gutters, and downspouts are in tip-top shape, efficiently channeling water away from your home’s foundation.
  
• Slope Sense: Avoid building or clearing land on steep slopes or mountain edges. If necessary, hire an expert to survey your property and recommend the best erosion control measures.
  
• Insurance Check: Update your home insurance policy — many don’t cover landslide or mudslide damage.
  

About Home Gnome: Home Gnome is where you’ll find all sorts of DIY and professional help for projects around your house, rental, or apartment.

Media resources

• 2023’s Most Landslide-Vulnerable Counties Ranking Results

Main Photo Credit: Oregon Department of Transportation | Wikimedia Commons | License

Kimberly Magerl

Kimberly Magerl is a writer and editor specializing in home improvements, lawn care, landscaping, and gardening. She enjoys growing orchids, tending to fruits and vegetables in her garden, and cooking with her home-grown herbs.

Posts by Kimberly Magerl