Preview: automated baseline. Built automatically from federal data and not yet checked by hand. Check every figure against your own records before you use it in a plan.

Platte County, WY

Risk-assessment baseline packet. County area 56031. Release 2026-10, data as of 2026-09-28.

Download the packet

PDF: PDF, for printing and reading. Word: Word document, tables ready to paste into a plan. Excel: Excel workbook, one sheet per section, full tables. JSON: Packet data (JSON), for analysts. Full packet as a web page. File manifest (checksums, source versions).

Plan clock

Approved, expires 2028-04-13

Plan
Region Seven, WY Hazard Mitigation Plan 2023 (FEMA plan 108836)
Approved
2023-04-14
Expires
2028-04-13
As of
2026-09-28
Days
563 days to expiry

Map group: Expires in 12 to 24 months.

What changed since your last plan (approved 2023-04-14)

New federal declarations
FM-5523-WY (1 declaration row; 1 counted incident)
Storm Events records since approval
221 (data through 2026-06-30)
Repetitive loss now
FMA RL 0, SRL 0 (44 CFR 77.2); any definition: 0
Repeat-flood change
First release: no prior release to compare.

Plan status for every jurisdiction in the plan

6 jurisdictions. Each row is that jurisdiction's own plan clock. Notes include other approved plans FEMA lists for the same jurisdiction.

JurisdictionTypeStatusPlanApprovedExpiresDays to expirynegative = days since expiryUpdate underwayNotes
Platte CountyCountyApproved, expires 2028-04-13Region Seven, WY Hazard Mitigation Plan 2023 (FEMA plan 108836)2023-04-142028-04-13563
Chugwater townTownApproved, expires 2028-04-13Region Seven, WY Hazard Mitigation Plan 2023 (FEMA plan 108836)2023-04-142028-04-13563
Glendo townTownApproved, expires 2028-04-13Region Seven, WY Hazard Mitigation Plan 2023 (FEMA plan 108836)2023-04-142028-04-13563
Guernsey townTownApproved, expires 2028-04-13Region Seven, WY Hazard Mitigation Plan 2023 (FEMA plan 108836)2023-04-142028-04-13563
Hartville townTownApproved, expires 2028-04-13Region Seven, WY Hazard Mitigation Plan 2023 (FEMA plan 108836)2023-04-142028-04-13563
Wheatland townTownApproved, expires 2028-04-13Region Seven, WY Hazard Mitigation Plan 2023 (FEMA plan 108836)2023-04-142028-04-13563

Plan 108836 also covers 15 other participants not listed on this page (named in the XLSX file).

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; whether the item is satisfied is decided by the plan and its reviewers. Full tables are in the downloads above.

Supports B1-a Hazards

14 of the 18 National Risk Index hazards apply here; omission evidence is shown only where NRI rates a hazard "Not Applicable", no federal declaration names it and Storm Events has no record of it since 1996.

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

Also check locally (not covered by NRI): 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 and expansive soils.

Check your state hazard mitigation plan's hazard list for this county; explain any hazard you drop.

Supports B1-b Location

  • Avalanche, Coastal Flooding, Earthquake, Hurricane, Landslide, Tornado, Tsunami, Volcanic Activity and Wildfire: Census tract rating counts from the National Risk Index tract table (see B1-f). Tract maps and place names are not in this packet.
  • Cold Wave, Drought, Hail, Heat Wave, Ice Storm, Lightning, Strong Wind and Winter Weather: Affects the whole planning area; national data do not distinguish locations within the county. Confirm locally.
  • 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 B1-c Extent

Storm Events records for 9 of 20 hazard groups, with the scale, observed range and worst recorded event for each; the others say local data required.

  • Hail: 4.25 in hail, 2019-07-04; same size also recorded on 2009-06-14, 2013-06-22, 2017-06-12
  • Thunderstorm Wind: 70 kt (81 mph) measured gust, Thunderstorm Wind, 2006-07-26
  • Tornado: F3 tornado, 1955-06-27, 2 mi path length (records before 1996 may include the whole path; rating and listing come from the county where the tornado began), 100 yd wide, $2,500 property; crops not recorded (1955 dollars), 3 direct injuries

Supports B1-d Previous occurrences

8 federal declaration rows for this area (6 counted incidents), each with type, dates and county Public Assistance dollars.

New since the last plan (approved 2023-04-14): FM-5523-WY.

1 statewide declaration listed separately.

Hazards with no recorded events are stated as such (8 of 18).

Storm Events history: 1,341 records (notable ones in the PDF, all of them in the Excel file).

Supports B1-e Probability

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

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

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

Supports B1-f Variation across the planning area

Range of census tract risk scores within the area for 18 hazards (3 tracts; rated tracts only).

6 member jurisdictions: plan clock, repeat-flood count, Public Assistance dollars and event records naming the place (starter, confirm locally).

Supports B2-a, B2-b Assets and impacts

Local data required

County-level starter. The plan must describe impacts for each participant and its own assets.

Storm Events damage since 2023-04-14: $26,000 in county-coded records (80 records); $108,000 reported for the zone (141 zone records). Data through 2026-06-30; nominal dollars.

Checklist of what to gather locally: Critical facilities and lifelines per hazard; A problem statement per participant per hazard; Changes in development in hazard-prone areas since the last approval, or a statement of none (E1-a); Future assets.

Supports B2-a Context

Population 8,567; building value $2,468,039,671 and agriculture value $121,338,813 (total, not at risk).

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

Supports B2-c Repetitive loss

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 and for each member community are in the packet.

Releases

Monthly releases are planned (not yet running); files for a release never change. Earlier releases will be listed here with what changed between them. All releases.

Cite this

Hazard Plain (2026). Platte County, WY: risk-assessment baseline packet, release 2026-10 (data as of 2026-09-28; County area 56031). Preview: automated baseline. https://hazardplain.org/wy/56031/ 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, its sources and its limits