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DNRC Headquarters
1539 Eleventh Ave. Helena, MT 59601
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Musselshell River Flood Maps Update

Musselshell Flooding
Photo credit: Chris Boyer, 2011

The Musselshell River communities are currently working with the Federal Emergency Management Agency (FEMA) and the Montana Department of Natural Resources and Conservation (DNRC) to update floodplain maps for the Musselshell River and some of its tributary streams. Many of the existing floodplain maps are based on data from the 1970's. New floodplain maps will depict the latest, most accurate flood risk data, allowing property owners and communities to better understand their flood risk and to protect themselves against flooding.

There will be insurance and development regulation implications for structures going into and coming out of the 100-Year Floodplain when the maps become effective (July 13, 2017 for the Roundup Area and expected late 2019 for the rest of the Musselshell communities). Property owners should educate themselves and prepare for the adoption of the new floodplain maps by taking the steps below. 

Know your Property's Flood Risk

Click the floodplain map viewer box below to view proposed map changes:

Preliminary Floodplain Map Viewer

Individual preliminary floodplain maps and studies can be viewed here:
Preliminary Maps and Studies

When finalized (expected late 2019), the new maps could have effects on some property owners in mapped floodplains. If you are currently or will be mapped into a 100-Year Floodplain, view these links about your flood risk areas:  100-Year Floodplain   Floodway (within 100-Year Floodplain)    500-Year Floodplai

Are you Newly Mapped in a 100-Year Floodplain?  Click here for Cost-Saving Insurance Options 

Appeal and Comment Period - October 18, 2018 - January 15, 2019

The 90-Day Appeal and Comment Period for the preliminary maps and studies runs through January 15, 2019.  Input on the preliminary maps and reports are encouraged and welcome. Find your individual county below for how to submit comments or appeals:

Petroleum County
All comments or appeals must be submitted to Petroleum County before mid-January 2019.  See: Petroleum County Comment and Appeal Form
100-Year Floodplain
   Floodway (within 100-Year Floodplain)    500-Year Floodplain
Petroleum County and Montana DNRC hosted a public open house in Mosby on 10/21/16.  For more information contact with Montana DNRC
Musselshell County
The comment period applies to the Musselshell River mainstem, except the Roundup Area (see below for more explanation).  All comments or appeals must be submitted to Musselshell County before mid-January 2019.  See: Musselshell County Comment and Appeal Form
100-Year Floodplain  500-Year Floodplain 
Musselshell County, Roundup and Montana DNRC hosted public open houses in Roundup and Melstone on 10/19/16, 10/20/16, and 1/31/17.
For more information contact with Montana DNRC
Rosebud County
All comments or appeals must be submitted to Rosebud County before mid-January 2019.  See: Rosebud County Comment and Appeal Form
100-Year Floodplain  500-Year Floodplain
Rosebud County and Montana DNRC hosted a public open house in Melstone on 10/20/16.
For more information contact with Montana DNRC
Wheatland County
An official comment and appeal period will open sometime in 2019.  Check back for more information.  Wheatland County, Harlowton and Montana DNRC hosted two public open houses in Harlowton on 10/25/17. View the meeting materials:   Presentation  100-Year Floodplain   Floodway   500-Year Floodplain 
Golden Valley County
An official comment and appeal period will open sometime in 2019.  Check back for more information.  Golden Valley County, Ryegate, Lavina, and Montana DNRC hosted two public open houses on 9/12/17.  View the meeting materials:   Presentation   100-Year Floodplain   Floodway    500-Year Floodplain 


Public Meetings

Roundup - Public Open House for Musselshell and Rosebud Counties:
Wednesday, October 3, 2018
Roundup Ambulance Barn
704 1st St. E., Roundup

Winnett - Planning Board Meeting for Petroleum County:
Wednesday, October 24, 2018
Petroleum County Courthouse
302 E. Main Street, Winnett

If you are unable to attend a meeting and/or need more information about this project, contact with Montana DNRC.

Roundup Area

FEMA map revisions for The Roundup Area have been through review and were issued on July 13, 2017.  The City of Roundup and Musselshell Counties held several public meetings about the map revisions in 2016 and 2017.   

Click City of Roundup Map Revisions to view the City map. To view the full Roundup Letter of Map Revision click here.

Click Musselshell County Map Revisions to view the County map. To view the full Musselshell County Letter of Map Revision click here.

Check out these fact sheets for more information about what it means to live in a flood zone:
Roundup: 100-Year Floodplain
Roundup: Floodway (Within 100-Year Floodplain) 
Roundup: 500-Year Floodplain

Come back for more information

We will update this website with new, relevant information as the Musselshell River Flood Maps Update project moves forward.




More Info

Draft Maps & Technical Data
Musselshell Watershed Coalition 

Contact Info

Floyd Fisher
Musselshell County
(406) 323-2777

Janel Tucek / Jay King
Petroleum County
(406) 429-5311

County Commissioners
Rosebud County
(406) 346-2251

Page Dringman
Golden Valley, Wheatland County, Ryegate
(406) 932-5470

Tiffany Lyden
Montana DNRC
(406) 444-0599