Hazard Plain Automated baseline

Rosebud County, MT

Risk-assessment baseline packet

County FIPS:
30087
Release:
2026-10
Data as of:
2026-09-30
Storm Events data through:
2026-06-30

Hazard Plain is an independent product built from public federal data. It is not a FEMA document and is not reviewed or endorsed by FEMA or any state agency.

Hazard Plain release 2026-10, as of 2026-09-30.

Summary

Plan status as of 2026-09-30: Approved, expires 2030-03-11. Plan: Eastern Montana Regional Hazard Mitigation Plan 2025 (FEMA plan 110310), approved 2025-03-12.

Since the plan was approved on 2025-03-12: 1 new hazard declaration (1 incident): DR-4902-MT (Severe Winter Storm and Straight-Line Winds).

NOAA Storm Events records since that date: 30 records (data through 2026-06-30).

Highest expected annual loss (FEMA National Risk Index, modeled total; see B1-a): Inland Flooding ($4,383,013 a year), Wildfire ($1,905,277) and Cold Wave ($1,778,987).

Repetitive-loss flood properties now: FMA RL 0, SRL 0 (44 CFR 77.2); any definition: 0.

The tables that follow are organized by the items of FEMA's Local Mitigation Plan Review Tool, Element B (B1-a to B2-c); each heading says which item its tables support.

Plan clock

Status:
Approved, expires 2030-03-11
Plan:
Eastern Montana Regional Hazard Mitigation Plan 2025 (FEMA plan 110310)
Approved:
2025-03-12
Days to expiry:
1,258

What changed since your last plan (approved 2025-03-12)

New federal declarations:
1 new hazard declaration (1 incident): DR-4902-MT (Severe Winter Storm and Straight-Line Winds)
Storm Events records since approval:
30 records (data through 2026-06-30)
Repetitive loss now:
FMA RL 0, SRL 0 (44 CFR 77.2); any definition: 0
Repeat-flood change:
this release sets the baseline count.

Sources: 1, 2, 4, 6 (numbered list at the end)

Plan status for every jurisdiction listed in this county

Source: 1

JurisdictionTypeStatusPlanApprovedExpiresDays to expirynegative = days since expiryNotes
Rosebud CountyCountyApproved, expires 2030-03-11Eastern Montana Regional Hazard Mitigation Plan 2025 (FEMA plan 110310)2025-03-122030-03-111,258this jurisdiction approved 2025-05-30
Colstrip cityCityApproved, expires 2030-03-11Eastern Montana Regional Hazard Mitigation Plan 2025 (FEMA plan 110310)2025-03-122030-03-111,258this jurisdiction approved 2025-12-05
Forsyth cityCityApproved, expires 2030-03-11Eastern Montana Regional Hazard Mitigation Plan 2025 (FEMA plan 110310)2025-03-122030-03-111,258this jurisdiction approved 2025-06-13

Plan 110310 covers 67 other participants, named in the Excel file.

State plan status and tribal plans in this state: see the state page.

Supports FEMA checklist item B1-a: hazard identification

Hazards NRI does not cover (local data needed)

  • dam failure (incl. upstream dams)
  • levee failure
  • flash flood as its own subtype
  • ice jams
  • debris flows
  • erosion (riverine and coastal)
  • land subsidence and sinkholes
  • expansive soils

The 18 National Risk Index hazards, ranked by expected annual loss (EAL)

Sources: 5, 6

Rank by EALHazardNRI risk ratingEAL ratingEAL buildingsmodeled dollars per yearEAL agriculturemodeled dollars per yearCost of expected deaths and injuriesFEMA's dollar value per year, not property damageEAL total (see note)modeled dollars per yearStorm Events records, 1996 to 2026-06-30countWhy this hazard can be left outNRI Not Applicable, no declaration and no Storm Events record since 1996Storm Events coverage note
1Inland FloodingRelatively LowRelatively Low$4,376,964$5,839$209$4,383,01328
2WildfireRelatively ModerateRelatively Moderate$1,806,188$1,306$97,784$1,905,2779
3Cold WaveRelatively ModerateRelatively Moderate$5,478$346,146$1,427,363$1,778,9872
4LightningRelatively LowRelatively Low$2,737n/a$146,786$149,5232
5Winter WeatherRelatively ModerateRelatively Moderate$33,675$118$113,155$146,948102
6HailRelatively LowVery Low$54,989$43,788$14,851$113,628298
7Strong WindRelatively LowVery Low$23,240$22,816$36,760$82,816276Includes 72 High Wind records (a NOAA non-thunderstorm wind type, outside NRI's Strong Wind definition).
8Heat WaveVery LowVery Low$1,736$7,236$72,866$81,8380No recorded events in Storm Events since 1996 (data through 2026-06-30).
9EarthquakeVery LowVery Low$34,001n/a$5,613$39,614Storm Events does not record earthquakes.
10TornadoVery LowVery Low$25,981$3,082$6,513$35,5764
11DroughtRelatively LowVery Lown/a$19,656n/a$19,6561
12Ice StormVery LowVery Low$2,312n/a$566$2,8793
13LandslideRelatively LowVery Low$1,678n/a$769$2,4470No recorded events in Storm Events since 1996 (data through 2026-06-30).
14AvalancheVery LowVery Low$0n/aunder $1under $10No recorded events in Storm Events since 1996 (data through 2026-06-30).
HurricaneNot ApplicableNot Applicable0NRI rates hurricane Not Applicable for this county, and no counted federal declaration for this county names it (EM-3253-MT names it but is not counted as a local occurrence; see B1-d).No recorded events in Storm Events since 1996 (data through 2026-06-30).

Total = buildings + agriculture + population equivalence; FEMA values each expected death (or 10 injuries) at $13.7 million (2024 dollars).

NRI risk rating combines expected annual loss with social vulnerability and community resilience; EAL rating rates expected annual loss alone. Both compare this county with all U.S. counties.

Local data needed: state and local landslide records (Storm Events records this hazard only in part).

Not applicable to this county per NRI, with no federal declaration and no Storm Events record since 1996: coastal flooding, tsunami and volcanic activity. That is the evidence for leaving them out of the plan.

The state hazard mitigation plan also lists hazards for this county; FEMA asks the plan to explain any hazard it leaves out.

Supports FEMA checklist item B1-b: hazard location

Affects the whole county (national data give no location within it): Cold Wave, Drought, Hail, Heat Wave, Ice Storm, Lightning, Strong Wind and Winter Weather.

Inland Flooding: The FEMA Flood Insurance Rate Map (FIRM) is the required location source for flooding. See the FEMA Flood Map Service Center (https://msc.fema.gov) for this county.

Hazards that vary within the county: highest-rated census tracts

Source: 5

HazardHighest-rated census tractsNRI risk rating, score 0 to 100
Avalanchetract 9404 (Very Low, 0.6); tract 2 (Very Low, 0.5)
Earthquaketract 1 (Relatively Low, 43.3); tract 2 (Very Low, 39.5); tract 9404 (Very Low, 34.3)
Hurricaneno tract has a National Risk Index rating for this hazard
Landslidetract 2 (Relatively Low, 94.9); tract 9404 (Relatively Low, 92.8); tract 1 (Relatively Low, 87.6)
Tornadotract 1 (Relatively Low, 31.1); tract 9404 (Very Low, 27.3); tract 2 (Very Low, 26.6)
Wildfiretract 2 (Very High, 99.2); tract 9404 (Very High, 99.1); tract 1 (Relatively High, 97.1)

Up to 3 census tracts per hazard, highest National Risk Index rating first, then highest score; a tract number is the Census tract number (for example 9404 is Census Tract 9404). FEMA's Resilience Analysis and Planning Tool maps the National Risk Index for every tract: https://www.fema.gov/emergency-managers/practitioners/resilience-analysis-and-planning-tool

Supports FEMA checklist item B1-c: hazard extent

Extent: scale, observed range and worst recorded event per hazard

Sources: 6, 7

HazardScaleRecordscount and yearsObserved rangeWorst recorded eventMost damaging (when different)How it applies to jurisdictionsNote
Avalanchenone (count and damage only)0Physical measure: in event narratives only (local data needed).
Cold/Wind Chill, Extreme Cold/Wind Chillwind chill2 records, 1998 to 2000 (2 zone-level)1 day to 7 days (median 4 days); 2 with a recorded value7 consecutive days, 1998-12-18 to 1998-12-24, zone-levelCountywide (zone-level records).Wind chill: in event narratives only (local data needed).
Frost/Freeze (outside NRI's Cold Wave definition)crop damage0Temperature: in event narratives only (local data needed).
DroughtU.S. Drought Monitor scale (D0 to D4)1 record, 2021 (1 zone-level)31 days; 1 with a recorded value31 days (1 month), 2021-08-01 to 2021-08-31, zone-levelCountywide (zone-level records).Storm Events enters a drought at D2 or worse east of the Rockies and D3 or worse from the Rockies west (NWS Instruction 10-1605); NRI drought counts D3 and D4 only.
EarthquakeModified Mercalli (local data)0Storm Events does not record earthquakes; the USGS earthquake catalog is the source.
Hailhail size (inches)333 records, 1958 to 20250.75 in to 6 in (median 1 in); 332 with a recorded value6 in hail, 1965-07-11Hail, 1993-08-21, $5,000 property; $5,000 crops (1993 dollars)Event records naming jurisdictions in the plan: Colstrip city (57 records), Forsyth city (54 records).
Excessive Heat, Heatheat index (in event narratives)0Heat index: in event narratives only (local data needed).
Hurricane, Tropical Storm, Tropical DepressionSaffir-Simpson0Storm Events files every zone of a storm's episode under the storm's type; flooding from the storm is filed as Flood or Flash Flood records.
Ice StormSperry-Piltz ice scale (local data)3 records, 1998 to 2009 (3 zone-level)No damage reported in 3 records.Countywide (zone-level records).Ice thickness: in event narratives only (local data needed).
Flash Flood, Flood, Lakeshore Flooddamage and flood days (flood depth: FIRM)28 records, 1999 to 2019Flood, 2011-05-21, $225,000 property; $0 crops (2011 dollars)Event records naming jurisdictions in the plan: Colstrip city (5 records), Forsyth city (5 records).Flood depth: see the FEMA Flood Insurance Rate Map. Storm Events damage is often $0 or blank for floods, major ones included; FEMA Public Assistance by declaration (B1-d) shows which floods cost the most.
Debris Flownone (count and damage only)0Physical measure: in event narratives only (local data needed).
Lightningannualized frequency (the measure FEMA's Local Mitigation Planning Handbook names)2 records, 1998 to 2001Lightning, 1998-07-05, $10,000 property; crops not reported (1998 dollars)Event records naming jurisdictions in the plan: Forsyth city (2 records).Storm Events lists lightning with damage or casualties; physical measure in event narratives only (local data needed).
High Wind and Strong Wind (outside NRI's Strong Wind definition)wind speed (kt and mph)72 records, 1999 to 2026 (72 zone-level)35 kt (40 mph) to 81 kt (93 mph) (median 52 kt (60 mph)); 72 with a recorded value81 kt (93 mph) measured gust, High Wind, 2006-02-01; NWS zone MTZ031Countywide (zone-level records).
Thunderstorm Windwind speed (kt and mph)218 records, 1960 to 202550 kt (58 mph) to 90 kt (104 mph) (median 56 kt (64 mph)); 201 with a recorded value90 kt (104 mph) estimated, Thunderstorm Wind, 2002-07-08Thunderstorm Wind, 2000-07-09, $10,000 property; crops not reported (2000 dollars)Event records naming jurisdictions in the plan: Forsyth city (41 records), Colstrip city (17 records).
TornadoEnhanced Fujita (Fujita before Feb 2007)9 records, 1980 to 2014F/EF0 to F/EF1 (median F/EF0); 9 with a recorded valueF1 tornado, 1980-06-14, 33 yd wide, damage not recorded (pre-1996 record)Event records naming jurisdictions in the plan: Forsyth city (1 record).Before 1996 a tornado is listed once, under the county where it began, with its whole path's rating and length; from 1996 on, each county lists its own segment. Length is not used to rank tornadoes (see Methods).
Wildfireacres burned (local data)9 records, 1998 to 2024 (8 zone-level)Wildfire, 2003-08-12, $200,000 property; crops not reported (2003 dollars); NWS zone MTZ058Event records naming jurisdictions in the plan: Colstrip city (1 record). Zone-level records (8) apply countywide.Acres burned: in event narratives only (local data needed).
Winter Storm, Heavy Snow, Blizzard, Lake-Effect Snow, Winter Weather, Sleetnone in data (snowfall: local data)102 records, 1996 to 2026 (102 zone-level)No damage reported in 102 records.Countywide (zone-level records).Snow depth: in event narratives only (local data needed).

Storm Events records are more complete after 1996; before 1996 only Tornado (from 1950), Hail and Thunderstorm Wind (from 1955) exist. Zone-level records whose zone no NWS zone-county file places in this county (mostly before 2020) are not counted here (the Methods page explains the zone matching).

Dollars are nominal (as reported), labeled with the year; not adjusted for inflation.

Supports FEMA checklist item B1-d: previous occurrences

Federal declarations for this county: 15 declarations covering 10 separate hazard incidents counted in this packet (declarations for the same incident count once; non-natural and evacuation-only declarations are not counted).

Federal disaster declarations for this county

Sources: 1, 2, 3

DeclaredIncident beganFEMA numberTypeTitleMapped hazardCounty Public Assistancefederal share obligated, nominal dollarsFlagsNotes
2026-04-072025-12-17DR-4902-MTMajor disasterSevere Winter Storm and Straight-Line WindsStrong Wind (primary); also designated: Winter Weather$20,410.71new since last plan; within last 5 years
2021-09-302021-08-08DR-4623-MTMajor disasterRichard Spring FireWildfire$4,302,288.01within last 5 years
2021-08-102021-08-10FM-5406-MTFire managementRichard Spring FireWildfireno Public Assistance recordedsame incident as DR-4623
2020-09-032020-09-03FM-5345-MTFire managementSnider/Rice Fire ComplexWildfireno Public Assistance recorded
2020-03-312020-01-20DR-4508-MTMajor disasterCOVID-19 PandemicNon-natural, not countedno Public Assistance recorded
2020-03-132020-01-20EM-3476-MTEmergencyCOVID-19Non-natural, not countedno Public Assistance recordedsame incident as DR-4508
2014-04-172014-03-01DR-4172-MTMajor disasterIce Jams and FloodingInland Floodingno Public Assistance recorded
2013-07-102013-05-19DR-4127-MTMajor disasterFloodingInland Flooding$60,726.88
2012-08-022012-06-25DR-4074-MTMajor disasterWildfireWildfire$1,219,499.10
2012-06-272012-06-25FM-2989-MTFire managementAsh Creek FireWildfireno Public Assistance recordedsame incident as DR-4074
2011-06-172011-04-04DR-1996-MTMajor disasterSevere Storms and FloodingInland Flooding$349,003.59
2005-09-132005-08-29EM-3253-MTEmergencyHurricane Katrina EvacuationHurricane: evacuation support, not a local hazard event; not countedno Public Assistance recorded
2000-08-302000-07-13DR-1340-MTMajor disasterWildfiresWildfirePA not declared for this county
1986-10-141986-09-25DR-777-MTMajor disasterSevere Storms & FloodingInland Floodingno Public Assistance recorded
1978-05-291978-05-29DR-558-MTMajor disasterSevere Storms & FloodingInland Floodingno Public Assistance recorded

County Public Assistance: applicants the FEMA record places in this county, including any state agencies FEMA files there; statewide rows are listed on the state page; federal share obligated, nominal dollars.

Statewide declarations

Source: 2

DeclaredIncident beganFEMA numberTypeTitleMapped hazard
1964-12-181964-12-18DR-182-MTMajor disasterSevere Winter StormWinter Weather
1964-06-091964-06-09DR-172-MTMajor disasterHeavy Rains & FloodingInland Flooding
1953-06-061953-06-06DR-5-MTMajor disasterFloodsInland Flooding

FEMA recorded these with designated area Statewide and no county, so they are listed on every county page in the state and not counted with county rows. Local data needed: whether each one affected this county.

11 Fire Management declarations (1973-08-16 to 1996-09-06) FEMA filed as Statewide with no county; each names one local fire. Listed on the state page.

Public Assistance filed under this county for declarations that do not list it: 2 rows, $395,168.61

Sources: 2, 3

FEMA numberDeclaredTitleApplicantPA obligatedfederal share obligated, nominal dollars
DR-1767-MT2008-06-13Severe Winter StormTongue River Electric Cooperative, Inc.$385,743.64
DR-1377-MT2001-05-28Severe Winter StormsDO NOT USE Northern Cheyenne Indian Tribe$9,424.97

FEMA's Public Assistance summaries file these applicants under this county, but FEMA's declaration rows for these disasters do not designate it (an electric cooperative or district serving several counties, for example). Not in any declaration row above and not counted.

Public Assistance not placed in any Montana county: 2 rows, $679,475.72; listed on the Montana state page.

Source: 3

Previous occurrences by hazard, with explicit no-event rows

Sources: 2, 6, 7

HazardStorm Events records, all years on file(years in the Period column)Since plan approvalrecordsIn the 12 months before plan approvalrecordsLast 5 yearsrecordsDeclared incidents, all yearsseparate disastersDeclared since approvalseparate disastersPeriodStatement
Avalanche0000001996 to 2026-06-30No recorded events, 1996 to 2026-06-30, NOAA NCEI Storm Events
Cold Wave2000001996 to 2026-06-30
Drought1000001996 to 2026-06-30
Earthquake000000Storm Events does not record earthquakes; the USGS earthquake catalog is the source.
Hail3331311001955 to 2026-06-30
Heat Wave0000001996 to 2026-06-30No recorded events, 1996 to 2026-06-30, NOAA NCEI Storm Events
Hurricane0000001996 to 2026-06-30No recorded events, 1996 to 2026-06-30, NOAA NCEI Storm Events
Ice Storm3000001996 to 2026-06-30
Inland Flooding28000501996 to 2026-06-30
Landslide0000001996 to 2026-06-30No recorded events, 1996 to 2026-06-30, NOAA NCEI Storm Events
Lightning2000001996 to 2026-06-30
Strong Wind290261364111955 to 2026-06-30Includes 72 High Wind records.
Tornado9000001950 to 2026-06-30
Wildfire9011401996 to 2026-06-30
Winter Weather1023317111996 to 2026-06-30

Notable Storm Events records

Sources: 1, 6, 7

DateEvent typeMagnitude or extentDamagenominal dollarsDeaths, injuriesdirect onlyLocationWhy listed
2021-08-01Drought$0 property; $0 crops, reported for the zone (2021 dollars)0, 0NWS zone MTZ031 (NORTHERN ROSEBUD), zone-levelB1-c worst recorded: Drought
2020-01-30Winter Weather$0 property; $0 crops, reported for the zone (2020 dollars)2, 2NWS zone MTZ058 (SOUTHERN ROSEBUD), zone-leveldeaths or injuries recorded
2011-05-21Flood$225,000 property; $0 crops (2011 dollars)0, 0NICHOLS to INGOMARB1-c worst recorded: Flash Flood, Flood, Lakeshore Flood
2009-02-19Winter Weather$0 property; $0 crops, reported for the zone (2009 dollars)2, 0NWS zone MTZ058 (SOUTHERN ROSEBUD), zone-leveldeaths or injuries recorded
2006-02-01High Wind81 kt (93 mph) measured gustdamage not reported0, 0NWS zone MTZ031 (NORTHERN ROSEBUD), zone-levelB1-c worst recorded: High Wind and Strong Wind
2003-08-12Wildfire$200,000 property; crops not reported, reported for the zone (2003 dollars)0, 0NWS zone MTZ058 (SOUTHERN ROSEBUD), zone-levelB1-c worst recorded: Wildfire
2002-07-08Thunderstorm Wind90 kt (104 mph) estimateddamage not reported0, 0HATHAWAYB1-c worst recorded: Thunderstorm Wind
2001-05-16Lightningdamage not reported0, 3FORSYTHdeaths or injuries recorded
1998-12-18Cold/Wind Chilldamage not reported0, 0NWS zone MTZ031 (ROSEBUD), zone-levelB1-c worst recorded: Cold/Wind Chill, Extreme Cold/Wind Chill
1998-07-05Lightning$10,000 property; crops not reported (1998 dollars)0, 0FORSYTHB1-c worst recorded: Lightning
1980-06-14TornadoF1, 33 yd widedamage not recorded (pre-1996 record)0, 0location not recordedB1-c worst recorded: Tornado
1965-07-11Hail6 indamage not recorded (pre-1996 record)0, 0location not recordedB1-c worst recorded: Hail

The full list is in the Excel file, sheet "B1-d Storm Events history" (779 rows).

Location is the place NOAA recorded, as written in its data; it need not be a jurisdiction in this plan.

Local data needed: state-declared emergencies, from your state emergency management agency (federal data do not include them).

Tribal and special-area declarations in this state are listed on the state page.

Supports FEMA checklist item B1-e: probability of future events

Probability: FEMA annualized frequency and descriptor per hazard

Sources: 5, 6

HazardFEMA annualized frequency (modeled)unit per rowUnitIn plain termsDescriptorDescriptor basisNRI events or days in its record period (hail, wind and tornado are area-weighted, so can be fractional)NRI periodLocationNote
Avalanche0.01events per yearabout 1 in 100 yearsPossibleFEMA annualized frequency (modeled)01994 to 2023 (30 years)see B1-f0.01 is NRI's minimum avalanche frequency for a county in an avalanche susceptibility zone; NRI records no avalanche here, so the descriptor reflects the floor, not local events.
Cold Wave5.05event-days per yearabout 5.05 days per yearPossible (from Storm Events: 2 of 30 years)event-days in 2 of 30 years, 1996 to 2025 (6.67%)962005-11-12 to 2024-11-12 (19 years)countywide
Drought63.8event-days per yearabout 63.8 days per yearPossible (from Storm Events: 1 of 30 years)event-days in 1 of 30 years, 1996 to 2025 (3.33%)2,2752000 to 2025 (25.25 years; D3 and D4 only)countywide
Earthquake0.000525annual probability at a locationchance a given location in the county has at least minor-damage shaking in a year: 0.0525%not shownmodeledsee B1-fNo descriptor (Storm Events does not record earthquakes).
Hail1.58events per yearabout 1.58 per yearHighly likelyFEMA annualized frequency (modeled)60.2 (modeled)1986 to 2023 (38 years)countywide
Heat Wave2.26event-days per yearabout 2.26 days per yearevent-days in 0 of 30 years, 1996 to 2025 (0%)21.72005-11-12 to 2024-11-12 (19 years)countywideNo Storm Events heat wave record, 1996 to 2025
Hurricaneevents per year1851 to 2024 (Atlantic)see B1-fNot Applicable in NRI for this county; no descriptor.
Ice Storm0.0149event-days per yearabout 0.0149 days per yearLikely (from Storm Events: 3 of 30 years)event-days in 3 of 30 years, 1996 to 2025 (10%)01946-12-31 to 2014-02-12 (67 years)countywide
Inland Flooding0.786event-days per yearabout 0.786 days per yearLikely (from Storm Events: 11 of 30 years)event-days in 11 of 30 years, 1996 to 2025 (36.7%)221996 to 2023 (28 years)see B1-f
Landslide2.59events per year (modeled)about 2.59 per yearHighly likelyFEMA annualized frequency (modeled)not shownmodeledsee B1-f
Lightning30.3days per year with a strikeabout 30.3 days per yearHighly likelyFEMA annualized frequency (modeled)not shown1995 to 2023 (29 years; CONUS)countywide
Strong Wind0.881events per yearabout 0.88 per yearLikelyFEMA annualized frequency (modeled)341986 to 2023 (38 years)countywide
Tornado0.286events per yearabout 1 in 4 yearsLikelyFEMA annualized frequency (modeled)not shown1950 to 2023 (EF2+); 1986 to 2023 (EF0-1)see B1-f
Wildfire0.00523annual probability at a locationchance a given location in the county burns in a year: 0.523%Likely (from Storm Events: 7 of 30 years)Storm Events records in 7 of 30 years, 1996 to 2025 (23.3%)not shownmodeledsee B1-fDescriptor from Storm Events, not NRI.
Winter Weather17.3event-days per yearabout 17.3 days per yearHighly likely (from Storm Events: 29 of 30 years)event-days in 29 of 30 years, 1996 to 2025 (96.7%)3292005-11-12 to 2024-11-12 (19 years)countywide

FEMA annualized frequency (modeled) is the National Risk Index v1.20 (December 2025) estimate of how often a hazard affects this county in a year; it is not recorded events divided by years, and its unit differs by hazard (events, event-days, or days with a lightning strike per year). For earthquake, wildfire, coastal flooding and tsunami the value is the chance (or number of events) at a location in the county, not across the county, so no "1 in N years" is given and the descriptor comes from Storm Events where it has a record (none for earthquake). The Methods page gives each hazard's method, from FEMA's National Risk Index Technical Documentation v1.20.

Where NRI gives event-days, the descriptor comes from the share of years with a Storm Events record; NRI's source records more events, so the two differ.

Descriptor scale used in this packet (defined per unit)

Sources: 5, 6

UnitDescriptorDefinition
events per yearHighly likely1 or more per year
events per yearLikelyabout once in 1 to 10 years
events per yearPossibleabout once in 10 to 100 years
events per yearUnlikelyless than once in 100 years
annual probabilityLikely10% to under 100% chance in a given year
annual probabilityPossible1% to under 10% chance in a given year
annual probabilityUnlikelyunder 1% chance in a given year
event-days (share of years)Highly likelyevent-days recorded in 90% or more of years
event-days (share of years)Likelyevent-days recorded in 10% to under 90% of years
event-days (share of years)Possibleevent-days recorded in some years but under 10% of years
lightning strike-daysHighly likelycloud-to-ground strikes on 1 or more days per year

Intensity bands: historical frequency (Storm Events)

Source: 6

HazardBandYearsEventscounty-coded recordsYears in periodEvents per yearevents / years
Hail1.00-1.99 in1996 to 2025160305.33
Hail2.00 in+1996 to 202522300.733
Thunderstorm Wind (counted as NRI Strong Wind)50-64 kt1996 to 2025165305.5
Thunderstorm Wind (counted as NRI Strong Wind)65 kt+1996 to 202533301.1
Thunderstorm Wind (counted as NRI Strong Wind)unmeasured or below 50 kt1996 to 20256300.2
TornadoEF0-11996 to 20254300.133
TornadoEF2-31996 to 20250300
TornadoEF4-51996 to 20250300
Tornadounrated (EFU)1996 to 20250300

The bands show how often events of each severity were recorded in this county, to profile how severe events have been (FEMA's probability item asks for the range of intensities).

Hail smaller than 1 inch is not counted: on 2010-01-05 the National Weather Service raised its severe-hail threshold from 3/4 inch to 1 inch, so smaller reports became less common after 2009 (NWS Service Change Notice 09-52). NRI hail frequency uses a 0.75 inch threshold.

Optional: future conditions. Not a required item in the 2025 FEMA Local Mitigation Planning Policy Guide; some states ask for it. The federal Climate Mapping for Resilience and Adaptation (CMRA) site gives county exposure to future climate conditions (https://resilience.climate.gov/).

Supports FEMA checklist item B1-f: hazards that vary across jurisdictions

Range of census tract risk within the county

Source: 5

HazardTractsrated of allNRI risk score, 0 to 100Tracts by rating
MinMedianMax
Avalanche2 of 40.50.50.6Very Low 2, Not Applicable 2
Cold Wave4 of 496.097.099.0Very High 4
Drought4 of 468.780.691.2Relatively Low 2, Very Low 2
Earthquake4 of 424.336.943.3Relatively Low 1, Very Low 3
Hail4 of 467.879.888.3Relatively Moderate 3, Relatively Low 1
Heat Wave4 of 431.344.054.6Relatively Low 4
Hurricane0 of 4Not Applicable 4
Ice Storm4 of 48.614.323.3Very Low 4
Inland Flooding4 of 453.193.996.8Very High 1, Relatively High 2, Relatively Moderate 1
Landslide4 of 454.690.294.9Relatively Low 3, Very Low 1
Lightning4 of 483.493.497.9Very High 1, Relatively High 3
Strong Wind4 of 451.967.280.4Relatively Moderate 3, Relatively Low 1
Tornado4 of 422.427.031.1Relatively Low 1, Very Low 3
Wildfire4 of 494.698.199.2Very High 2, Relatively High 1, Relatively Moderate 1
Winter Weather4 of 497.498.499.5Very High 4

Drought: Agriculture is all of NRI's expected annual loss for this hazard in the county, so the tract range mostly reflects where crop and livestock value is.

Rated tracts only: No Rating (score 0.0), Not Applicable and Insufficient Data tracts are counted but not used for the minimum, median and maximum.

The score ranks a tract against all U.S. tracts (100 = highest). The rating is FEMA's category for the tract's risk value, computed differently, so the two can disagree.

Frequency data for cold wave, drought, hail, heat wave, ice storm, lightning, strong wind and winter weather are county-wide or coarse (49 km grid or NWS zone), the same for every jurisdiction; the tract range mostly reflects where buildings and people are (crop and livestock value where a line above names agriculture).

Each jurisdiction (starting figures from federal data)

Sources: 1, 3, 4, 6

JurisdictionTypePlan statusRepetitive lossFMA RL and SRL (44 CFR 77.2); repeat-flood, any definitionPublic Assistance to this jurisdictionFEMA records matched by applicant name; federal share obligated, nominal dollarsEvent records naming this placeall years; since its plan
Rosebud CountyCountyApproved, expires 2030-03-11FMA RL 0, SRL 0; any 0$389,214.290 total; 0 since its plan
Colstrip cityCityApproved, expires 2030-03-11FMA RL 0, SRL 0; any 0no Public Assistance recorded80 total; 0 since its plan
Forsyth cityCityApproved, expires 2030-03-11FMA RL 0, SRL 0; any 0no Public Assistance recorded103 total; 2 since its plan

Repetitive-loss counts are for whole NFIP communities, which can extend beyond this county (see the note in B2-c).

County Public Assistance in B1-d also includes applicants filed under the county that are not jurisdictions in this plan (for example state agencies, special districts and nonprofits), so the jurisdiction rows add up to less.

Supports FEMA checklist items B2-a and B2-b: vulnerability and potential impacts

Local data needed

The table below gives county-level starting figures; the plan describes impacts for each jurisdiction and its own assets.

  • Critical facilities and lifelines per hazard
  • A problem statement per jurisdiction per hazard
  • Changes in development in hazard-prone areas since the last approval, or a statement of none (E1-a)
  • Future assets

County-level starter: exposure, expected annual loss and damage since the plan

Sources: 1, 2, 3, 5, 6, 7

HazardBuilding exposuremodeled dollarsAgriculture exposuremodeled dollarsPopulation exposedpeopleEAL buildingsmodeled dollars per yearEAL agriculturemodeled dollars per yearCost of expected deaths and injuriesFEMA's dollar value per year, not property damageEAL as % of exposurebuildings; agriculture where notedStorm Events damage since 2025-03-12county-coded records, property plus crops, nominal dollarsZone-level damage since planproperty plus crops, reported for the zonePublic Assistance since plannominal dollars; see noteNote
Avalanche$0n/aunder 1$0n/aunder $1building exposure is 0 in NRI
Cold Wave$2,565,452,763$111,547,6338,302$5,478$346,146$1,427,3630.000214%
Droughtn/a$10,015,011n/an/a$19,656n/a0.196% (agriculture)NRI has no building exposure for this hazard; agriculture shown
Earthquake$4,500,481,859n/a8,329$34,001n/a$5,6130.000756%
Hail$2,565,452,763$111,547,6338,302$54,989$43,788$14,8510.00214%$0
Heat Wave$2,565,452,763$111,547,6338,302$1,736$7,236$72,866under 0.0001%
HurricaneNot Applicable in NRI for this county
Ice Storm$2,565,452,763n/a8,302$2,312n/a$566under 0.0001%
Inland Flooding$2,563,804,833$350,8724$4,376,964$5,839$209n/a (see note)NRI counts the full building value of any census block with some flood loss; this is not the value of buildings in the floodplain. Use local FIRM overlays for B2-a/B2-b.
Landslide$68,437,828n/a328$1,678n/a$7690.00245%
Lightning$2,565,452,763n/a8,302$2,737n/a$146,7860.000107%
Strong Wind$2,565,452,763$111,547,6338,302$23,240$22,816$36,7600.000906%$0$0$20,410.71
Tornado$2,565,452,763$111,547,6338,302$25,981$3,082$6,5130.00101%
Wildfire$593,890,708$60,319,3983,123$1,806,188$1,306$97,7840.304%
Winter Weather$2,565,452,763$111,547,6338,302$33,675$118$113,1550.00131%$0$20,410.71

Totals since 2025-03-12 (Storm Events through 2026-06-30): 22 county-coded records, 22 with a damage value recorded (including $0), $0; 8 zone-level records, 8 with a damage value recorded (including $0), $0 reported for the zone; Public Assistance: $20,410.71 on 1 counted declaration.

FEMA does not split Public Assistance by hazard. A declaration mapped to several hazards is listed under each of them with its full amount, so the per-hazard column does not add up to the total; the unit total counts each declaration once.

NRI computes earthquake exposure on its own basis, so it exceeds the county building value in B2-a.

Supports FEMA checklist item B2-a: vulnerability (county context)

County context

Source: 5

MeasureValue
Population8,302
Building value (total, not at risk)$2,565,452,763
Agriculture value (total, not at risk)$111,547,633
NRI risk rating (all hazards)Relatively Low
Expected annual loss, buildings and agriculture, all hazards$6,818,967
Expected annual loss, population equivalence, all hazards (NRI values each statistical life at $13.7M; a modeled value of expected deaths and injuries, not property damage)$1,923,235
Social vulnerability ratingVery High
Community resilience ratingVery Low
NRI versionDecember 2025

FEMA's all-hazard expected annual loss adds buildings, agriculture and population equivalence; this table gives the property part and the population-equivalence part as separate rows.

Social vulnerability: higher means people are more likely to be harmed and slower to recover. Community resilience: lower means the community is less able to recover. High social vulnerability and low resilience both raise the NRI risk rating.

Supports FEMA checklist item B2-c: repetitive loss properties

Repetitive loss in this county, both definitions

Sources: 1, 4

DefinitionPropertiesSevere repetitive lossProperties
Repetitive loss, FMA definition (44 CFR 77.2)0Severe repetitive loss, FMA definition (44 CFR 77.2)0
Repetitive loss, NFIP insurance definition0Severe repetitive loss, NFIP insurance definition0

The state NFIP coordinator's list, the source FEMA's Handbook names, often uses the NFIP insurance definition (second row).

Repeat-flood properties: county total and NFIP communities

Sources: 1, 4

ScopeRL, FMApropertiesSRL, FMApropertiesRL, NFIPpropertiesSRL, NFIPpropertiesAny categorypropertiesMitigatedpropertiesCurrently insuredproperties
County total0000000

Repeat-flood properties by jurisdiction in the plan (NFIP community)

Sources: 1, 4

JurisdictionNFIP community IDRL, FMApropertiesSRL, FMApropertiesRL, NFIPpropertiesSRL, NFIPpropertiesAny categorypropertiesMitigatedpropertiesCurrently insuredproperties
Rosebud County3000690000000
Colstrip city3001840000000
Forsyth city3000700000000

Counts by occupancy group for each jurisdiction are in the Excel file, sheet "B2-c Jurisdictions".

Jurisdiction rows are whole NFIP communities and need not add up to the county total: a community that extends into another county is counted in full on each jurisdiction row, while the county table counts only its part in this county.

County repeat-flood properties by occupancy group: 0 in every occupancy group.

Sources: 1, 4

FMA RL and FMA SRL are the Flood Mitigation Assistance definitions (44 CFR 77.2), the ones the FEMA Local Mitigation Planning Policy Guide cites. NFIP repetitive loss (the FEMA insurance definition) is 2 or more claims over $1,000 in 10 years, and a property can leave that group once it is mitigated. Also shown: NFIP severe repetitive loss, any category, mitigated and currently insured. The Methods page gives the OpenFEMA field details.

Counts are aggregates of FEMA's public NFIP Multiple Loss Properties file (FEMA's data date 2026-08-02; file version 2026-08-04). No property is identified. County assignment is FEMA's geocode.

In this county 0 properties are FMA repetitive loss but not NFIP repetitive loss, and 0 properties are NFIP repetitive loss but not FMA repetitive loss.

Exact counts; no count suppression.

Sources

Tables cite these sources by number. The full list, for the plan's bibliography (FEMA review item A4-a):

  1. FEMA, OpenFEMA HazardMitigationPlanStatuses v1, version 2026-09-29T134039Z, pulled 2026-09-30, https://www.fema.gov/api/open/v1/HazardMitigationPlanStatuses (API)
  2. FEMA, OpenFEMA DisasterDeclarationsSummaries v2, version 2026-09-29T162832Z, pulled 2026-09-30, https://www.fema.gov/api/open/v2/DisasterDeclarationsSummaries (API)
  3. FEMA, OpenFEMA PublicAssistanceFundedProjectsSummaries v1, version 2026-09-29T150754Z, pulled 2026-09-30, https://www.fema.gov/api/open/v1/PublicAssistanceFundedProjectsSummaries (API)
  4. FEMA, OpenFEMA NfipMultipleLossProperties v1, version 2026-08-04T164045Z, pulled 2026-09-30, https://www.fema.gov/api/open/v1/NfipMultipleLossProperties (API)
  5. FEMA, FEMA National Risk Index 1.20.0 (December 2025), county and census tract tables, version 1.20.0, pulled 2026-09-30, https://www.fema.gov/about/reports-and-data/openfema/nri/v120/NRI_Table_Counties.zip (download, 25 MB), https://www.fema.gov/about/reports-and-data/openfema/nri/v120/NRI_Table_CensusTracts.zip (download, 635 MB)
  6. NOAA NCEI, NOAA NCEI Storm Events Database, details files (csvfiles v1.0), version c20260918, pulled 2026-09-30, https://www.ncei.noaa.gov/pub/data/swdi/stormevents/csvfiles/
  7. NOAA National Weather Service, NWS county-public forecast zones correlation file, version bp03mr20 to bp16ap26 (11 files; newest bp16ap26), pulled 2026-09-30, https://www.weather.gov/gis/ZoneCounty
  8. U.S. Census Bureau, Census 2024 Gazetteer, 2020 place by county, CT county-to-cousub crosswalk, version 2024-gazetteer, pulled 2026-09-30, https://www2.census.gov/geo/docs/maps-data/data/gazetteer/2024_Gazetteer/2024_Gaz_counties_national.zip, https://www2.census.gov/geo/docs/maps-data/data/gazetteer/2024_Gazetteer/2024_Gaz_cousubs_national.zip, https://www2.census.gov/geo/docs/maps-data/data/gazetteer/2024_Gazetteer/2024_Gaz_place_national.zip, https://www2.census.gov/geo/docs/maps-data/data/gazetteer/2024_Gazetteer/2024_Gaz_unsd_national.zip, https://www2.census.gov/geo/docs/maps-data/data/gazetteer/2024_Gazetteer/2024_Gaz_elsd_national.zip, https://www2.census.gov/geo/docs/maps-data/data/gazetteer/2024_Gazetteer/2024_Gaz_scsd_national.zip, https://www2.census.gov/geo/docs/reference/codes2020/national_place_by_county2020.txt, https://www2.census.gov/geo/docs/reference/ct_change/ct_cou_to_cousub_crosswalk.xlsx (used to match place names and codes; no table prints its values)

What this packet is and what the plan adds

This packet is the federal data for the plan's risk assessment, organized by the items of FEMA's Local Mitigation Plan Review Tool, Element B. Each section heading names the item its tables support; the plan and FEMA's review decide whether the item is met.

The plan adds what only the community has: local data on assets, critical facilities, development and each jurisdiction's impacts; local hazard history, including state-declared emergencies; the mitigation strategy; and adoption.

How the federal data are built: National Risk Index values are FEMA's model, not counts of events. Storm Events is more complete from 1996; zone-level records are placed by forecast zone, not by location in the county. Public Assistance for a jurisdiction is matched by applicant name. The Methods page gives every rule and the known edge cases.

OpenFEMA disclaimer

This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).

Reuse, citation and corrections

Reuse and citation: Hazard Plain text and tables are licensed under Creative Commons Attribution 4.0 International (CC BY 4.0, https://creativecommons.org/licenses/by/4.0/); credit Hazard Plain and the release. The underlying federal data are public domain; OpenFEMA data are also subject to the OpenFEMA terms and conditions.

Cite this: Hazard Plain (2026). Rosebud County, MT: risk-assessment baseline packet, release 2026-10 (data as of 2026-09-30; County FIPS 30087). Automated baseline. https://hazardplain.org/mt/30087/ Built from FEMA OpenFEMA, the FEMA National Risk Index and NOAA NCEI Storm Events; source versions in the packet's Sources list.

Corrections: to report an error, name the packet, the table and what your records show. Contact: contact@hazardplain.org

Hazard Plain release 2026-10. As of 2026-09-30; Storm Events data through 2026-06-30. Automated baseline.