Automated baseline from FEMA and NOAA data, release 2026-10.

Slope County, ND

Risk-assessment baseline packet. County FIPS 38087. Release 2026-10, data as of 2026-09-30.

Summary

Plan status as of 2026-09-30: Expired on 2023-12-20. Plan: Bowman County and Slope County, ND Hazard Mitigation Plan 2018 (FEMA plan 105540), approved 2018-12-21.

Since the plan was approved on 2018-12-21: no new hazard declaration and 121 NOAA Storm Events records; details under "What changed since your last plan".

Highest expected annual loss (FEMA National Risk Index, modeled total; see B1-a): Cold Wave ($597,348 a year), Inland Flooding ($219,920) and Hail ($96,458).

The packet's tables are organized by the items of FEMA's Local Mitigation Plan Review Tool, Element B (B1-a to B2-c); the summaries below follow the same order.

Download the packet

Full packet as a web page. File manifest (checksums, source versions).

Plan clock

Expired on 2023-12-20

Plan:
Bowman County and Slope County, ND Hazard Mitigation Plan 2018 (FEMA plan 105540)
Approved:
2018-12-21
Days since expiry:
1,015
Update underway:
none recorded in FEMA's plan tracker

Until a new plan is approved, FEMA mitigation project grants (HMGP, FMA) need a FEMA exception (44 CFR 201.6(a)(3)).

What changed since your last plan (approved 2018-12-21)

New federal declarations:
no new hazard declaration; 2 COVID-19 declarations (not counted)
Storm Events records since approval:
121 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.

Plan status for every jurisdiction listed in this county

3 jurisdictions. Each row is that jurisdiction's own plan clock.

JurisdictionTypeStatusPlanApprovedExpiresDays to expirynegative = days since expiry
Slope CountyCountyExpired on 2023-12-20Bowman County and Slope County, ND Hazard Mitigation Plan 2018 (FEMA plan 105540)2018-12-212023-12-20-1,015
Amidon cityCityExpired on 2023-12-20Bowman County and Slope County, ND Hazard Mitigation Plan 2018 (FEMA plan 105540)2018-12-212023-12-20-1,015
Marmarth cityCityExpired on 2023-12-20Bowman County and Slope County, ND Hazard Mitigation Plan 2018 (FEMA plan 105540)2018-12-212023-12-20-1,015

Plan 105540 lists 4 other participants: Bowman city (Bowman County); Bowman County; Rhame city (Bowman County); Scranton city (Bowman County).

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

What the packet contains

Sections in FEMA checklist order; each heading names the review item its tables support. Full tables are in the downloads above.

Supports FEMA checklist item B1-a Hazard identification

13 of the 18 National Risk Index hazards apply here.

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

Highest expected annual loss (NRI, modeled): Cold Wave, Inland Flooding and Hail.

Not covered by NRI (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 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

  • Cold Wave, Drought, Hail, Heat Wave, Ice Storm, Lightning, Strong Wind and Winter Weather: affects the whole county; national data give no location within it.
  • Earthquake, Hurricane, Landslide, Tornado and Wildfire vary within the county; the packet lists the highest-rated census tracts for each.
  • 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.

Supports FEMA checklist item B1-c Hazard extent

Storm Events records for 11 of the 20 NOAA event-type groups mapped to the 18 hazards, with the scale, observed range and worst recorded event for each; the others say which local data are needed.

Worst recorded tornado, hail and thunderstorm wind (the three event types on record since the 1950s; the packet has every group):

  • Hail: 4.5 in hail, 2003-07-17
  • Thunderstorm Wind: 124 kt (143 mph), measurement type not recorded, Thunderstorm Wind, 1997-09-15
  • Tornado: F1 tornado, 1991-06-08, 0.1 mi path length (whole path, pre-1996), 7 yd wide, $2,500 property; crops not recorded (1991 dollars); same rating, casualties and property damage also recorded on 1972-05-19

Supports FEMA checklist item B1-d Previous occurrences

Federal declarations for this area: 10 declarations covering 7 separate hazard incidents counted in this packet; each with type, dates and county Public Assistance dollars.

New since the last plan (approved 2018-12-21): DR-4509-ND and EM-3477-ND.

2 statewide declarations listed separately.

Hazards with no Storm Events record and no federal declaration are stated as such (8 of 18).

Storm Events history: 381 records (notable ones in the PDF, all of them in the Excel file).

Supports FEMA checklist item B1-e Probability of future events

FEMA annualized frequency (modeled) for each hazard, with a descriptor from a scale defined in the packet.

  • Highly likely: Hail, Lightning, Strong Wind and Winter Weather
  • Likely: Cold Wave, Drought, Landslide, Tornado and Wildfire
  • Possible: Heat Wave and Inland Flooding

Historical frequency by intensity band (tornado, hail, wind): 9 bands from Storm Events.

Supports FEMA checklist item B1-f Hazards that vary across jurisdictions

Range of census tract risk scores within the area for 14 of the 18 hazards (1 tract; rated tracts only).

3 jurisdictions: plan clock, repeat-flood count, Public Assistance dollars and event records naming the place (starting figures from federal data).

Supports FEMA checklist items B2-a and B2-b Vulnerability and potential impacts

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

Storm Events damage since 2018-12-21: $32,000 in county-coded records (42 records); $0 reported for the zone (79 zone records). Data through 2026-06-30; nominal dollars.

Local data needed

To gather:

  • 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

Supports FEMA checklist item B2-a Vulnerability (county context)

Population 699; building value $245,792,852 and agriculture value $61,725,324 (total, not at risk).

National Risk Index rating Very Low; social vulnerability Very Low; community resilience Very Low.

Supports FEMA checklist item B2-c Repetitive loss properties

Repetitive-loss properties, FMA definition (44 CFR 77.2): 0 repetitive loss, 0 severe repetitive loss. NFIP insurance definition: 0 and 0.

Mitigated 0; insured 0; NFIP data as of 2026-08-02. Counts by occupancy group and for each jurisdiction are in the packet.

Releases

Each release is dated; this is release 2026-10. It was first published 2026-09-30; its files do not change. Later releases will be listed here with what changed between them. All releases.

Cite this

Hazard Plain (2026). Slope County, ND: risk-assessment baseline packet, release 2026-10 (data as of 2026-09-30; County FIPS 38087). Automated baseline. https://hazardplain.org/nd/38087/ Built from FEMA OpenFEMA, the FEMA National Risk Index and NOAA NCEI Storm Events; source versions in the packet's Sources list.

Source citations for the plan's bibliography (8)

How this packet is built: methods and sources