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DNRC Headquarters
1539 Eleventh Ave. Helena, MT 59601
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Madison-Ruby-Jefferson River Watersheds Flood Maps Update

Madison, Jefferson, Gallatin, and Broadwater Counties have been working with the Federal Emergency Management Agency (FEMA) and Montana Department of Natural Resources and Conservation (DNRC) to produce new floodplain maps for portions of the Madison, Ruby, Jefferson, Beaverhead and South Boulder Rivers, and Mill and Indian Creeks.  See project extents here.

Updated floodplain maps will depict the latest, most accurate flood risk data, and will eventually result in updated FEMA floodplain maps. Most of the existing FEMA floodplain maps and Madison County flood prone maps are based on data from the 1980s and 1990s. For more information, see: Floodplain FAQs , Flood Study Process and Maps and Technical Reports.

Public Open House Meetings Were Held:
March 9, 2021 | Madison River | view slides   view video recording
March 10, 2021 | Jefferson River & S. Boulder R. | view slides   view video recording
March 11, 2021 | Ruby & Beaverhead Rivers, Sheridan & Twin Bridgesview slides   view video recording

Madison, Jefferson, Gallatin, and Broadwater Counties and Montana DNRC hosted virtual public open house meetings about the draft floodplain maps on March 9, 10, and 11, 2021. Meeting slides and recordings will be posted above.  Click on the green arrow next to your county below for additional meeting materials.

View Draft Maps


*please be patient while the data loads on the viewer*

View individual draft maps and reports here:  Maps and Technical Reports   
Get general information on floodplain designations referenced on the maps: 100 Year Floodplain   Floodway Area (within a 100 year Floodplain)    500 Year Floodplain

Draft maps and studies need to go through a lengthy technical and public review process. When finalized, new maps could have effects on some property owners in mapped 100-year floodplains. Click on your county below to learn about the floodplain designations referenced on the maps, community meetings, and other information:

Gallatin County and the City of Three Forks
For landowners in Gallatin County, virtual public meetings were held:
For landowners in the City of Three Forks, open house meetings were held:
  • January 6, 2021 | City of Three Forks Floodplain Mapping Update | To view the slides presented click here
  • December 2, 2020 | City of Three Forks Mitigation meeting | To view a video of the meeting click here 
  • November 10, 2020 City of Three Forks city council meeting | To view the slides presented click here.

Madison County and the Towns of Ennis, Twin Bridges, and Sheridan 
Virtual Public Meetings were held:

Jefferson County
A Virtual Public Meeting was held: 

Broadwater County 
A Virtual Public Meeting was held:


Appeal and Comment information

The communities, state, and FEMA welcome feedback as an important part of the mapping update process. If you have new information or would like to comment on the draft maps please click here. FEMA will open a formal 90 day appeal and comment period around early to mid 2023 (please check back for updates). 

Public Meetings Held Virtually

March 9, 2021 | Madison River focus | view slides  view video recording
March 10, 2021 | Jefferson River & S. Boulder R. focus | view slides   view video recording
March 11, 2021 | Ruby & Beaverhead Rivers, Sheridan & Twin Bridges focus | view slides   view video recording

Additional public meetings may be scheduled in the future.  Check back for updates. 

Big Hole River Floodplain Maps

A flood study and floodplain maps for the Big Hole River were produced in 2015. The Big Hole River floodplain maps and study information in Madison County will eventually be incorporated into preliminary FEMA floodplain maps at the same time as the rest of Madison County's draft floodplain maps.  Preliminary FEMA floodplain maps will go through a public review process before they are finalized.  

Know your property's flood risk

Floodplain maps indicate areas of flood risk. Once this project is complete, updated flood risk information  will be reflected on new and updated FEMA Flood Insurance Rate Maps.  These maps will provide more accurate, current, and detailed information about flood risk areas.

New floodplain studies involve collecting and analyzing data, including: topography, hydrology analyses and hydraulic analyses.  

Project Timeline

Come back for more information

We will update this website with new, relevant information as this project progresses. 

More Info

Floodplain FAQs

Maps and Technical Reports

Flood Study Process


Madison County

Cody Marxer
Floodplain Administrator
(406) 872-6359

Town of Ennis
Town of Twin Bridges

Jonathan Weaver
Floodplain Administrator
(406) 449-8627

Town of Sheridan

Bob Stump
Mayor/Floodplain Administrator
(406) 842-5431

Gallatin County

Sean O'Callaghan
Floodplain Administrator
(406) 582-3130

City of Three Forks

Kelly Smith
Floodplain Administrator
(406) 285-3431

Jefferson County

Megan Bullock
Floodplain Administrator
(406) 225-4126

Broadwater County

Jerry Grebenc
Floodplain Administrator
(406) 449-8627

DNRC Contacts

Nadene Wadsworth
DNRC Outreach Specialist
(406) 444-6732

Tiffany Lyden
DNRC Outreach Specialist
(406) 444-0599