257 flood insurance claims·$854,701 paid·2 federal flood & hurricane disasters
Share of the whole county outline, rivers and lakes included; parts FEMA hasn’t mapped count as zero.
Shaded areas are FEMA’s mapped flood hazard zones in and around Cascade County, Montana. Zoomed out they are simplified; at street level the map switches to FEMA’s exact layer. Tap anywhere to check that spot, or search an address above.
Flash flooding and river flooding from summer thunderstorms and spring snowmelt equally dominate the flood character of Cascade County, Montana, with each accounting for 15 events over the last 30 years and resulting in a combined two deaths. Recent hazards are illustrated by a stationary storm on July 31, 2025, that produced flash flooding in the Great Falls urban area with one gauge reporting 2.25 inches of rain in an hour. Additionally, lingering snowpack accelerated by moderate rainfall caused Belt Creek to flood in May 2023, impacting areas within the Lewis & Clark National Forest, closing Sluice Boxes State Park, and flooding yards and fields between Armington Junction and Sluice Boxes.
Property owners should note historical claims data across various FEMA zones. Zone A recorded the highest impact with 147 claims, an average payout of $6,703, and an average recorded water depth of 3 inches. Zones with unknown or X designations also experienced claims, including 41 claims in Zone UNKNOWN averaging $2,809 and 2 inches of water, 28 claims in Zone X_SHADED averaging $1,089 and 1 inch of water, 18 claims in Zone X averaging $8,610 and 2 inches of water, and 18 claims in Zone X_UNSHADED averaging $1,716 and 2 inches of water. Residents located in Zone A and near creeks, streams, and burn scars should pay the most attention to potential flood risks.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
24% of Cascade County’s flood insurance claims were on properties rated outside FEMA’s high-risk zones.
193 NFIP claims with a recorded rated flood zone, 1978 to date. The zone is the one FEMA used to rate that policy, which may not match today’s map. Source: OpenFEMA NFIP claims.
In flood insurance claims here that reported a flood depth, the average was 2 inches.
Drawn to scale against an 80-inch door. Even a few inches soaks flooring, the bottom of the drywall and anything plugged in near the floor.
Average of the depths reported on claims (zero and implausible values left out); FEMA’s record doesn’t say exactly where each depth was measured. Source: OpenFEMA NFIP claims.
The worst year was 1981, with 60 claims and $98,550 paid, the year of Severe Storms & Flooding.
Bar height is scaled by square root so ordinary years stay visible next to the worst one. NFIP claims by year of loss. Source: OpenFEMA.
19 NOAA storm reports from Cascade County describe what happened, in the words of the forecasters who covered it. Read the Montana flood stories →
7 federal disaster declarations since 1975, 2 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Severe Storms And Flooding | Apr 4, 2011 |
| Hurricane Katrina Evacuation | Aug 29, 2005 |
| Wildfires | Jul 13, 2000 |
| Severe Storms & Flooding | May 27, 1981 |
| Rains, Showmelt, Storms & Flooding | Jun 28, 1975 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
30 since 1996: 15 flash floods and 15 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flash Flood | Jul 31, 2025 | — |
| Flood | May 17, 2023 | $60,000 · 2 killed |
| Flood | May 6, 2023 | — |
| Flash Flood | Jun 5, 2023 | $50,000 |
| Flash Flood | Jun 3, 2021 | — |
| Flood | Jul 23, 2020 | — |
| Flood | May 27, 2019 | — |
| Flash Flood | Jun 27, 2019 | — |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Flash Flood · Jul 31, 2025. An upper-level shortwave combined with monsoon moisture brought a few severe thunderstorms and localized areas of heavy rainfall to North-Central MT. This resulted in isolated large hail, flooding, and a landspout. A stationary storm developed directly over the Great Falls urban area; this produced heavy rainfall and flash flooding in the city, with one gauge reporting 2.25 inches of rain in an hour. Another thund…
Flood · May 17, 2023. Spring rains across the area resulted in additional high elevation snowmelt which led to elevated water levels along many creeks and streams. Belt Creek flooded for a second time this month. Water levels crested at 6.78 feet at the river gauge along Belt Creek near Monarch. Water briefly impacted Sluice Boxes State Park's entrance parking lot and flooded primarily fields and driveways from Sluice Boxes northward t…
Flood · May 6, 2023. Lingering snowpack in the higher elevations of the Little Belt Mountains began to melt in early May. This melting was accelerated by moderate rainfall. Belt Creek ultimately flooded, impacting areas within the Lewis & Clark National Forest to near the community of Belt. Sluice Boxes State Park's main entrance was flooded with the park ultimately closed for a period of time. Some homes between Armington Junction an…
Flash Flood · Jun 5, 2023. Several rounds of rain and thunderstorms affected much of Montana during the first half of June. Flash flooding occurred across portions of the region, especially across Fergus County as well as the Rocky Mountains. Fergus County was hit exceptionally hard as several days of occasional heavy rain exasperated area creeks and streams. Casino Creek, located south of Lewistown, was washed out in at least two locations…
National Weather Service narratives, lightly trimmed. Source: NOAA Storm Events Database.
Every colour on the map above is a place on this drawing: where the ground sits relative to the flood FEMA plans for.
If a building in Cascade County is in a high-risk zone (A or V) and its mortgage comes from a federally regulated or insured lender, or is federally backed, flood insurance is required.
Outside those zones it is optional, and often worth having: from 2014 to 2024 nearly one-third of NFIP claims came from outside the high-risk Special Flood Hazard Area. Since Risk Rating 2.0, NFIP premiums are set for each building, so the only reliable price is a quote: FloodSmart.gov or a local agent.