Photo credit: Chris Boyer, 2011

The Musselshell River communities have been working with the Montana Department of Natural Resources and Conservation (DNRC) and the Federal Emergency Management Agency (FEMA) 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.

New floodplain maps for Musselshell, Rosebud, and Petroleum Counties became effective 11/15/19. New floodplain maps for Golden Valley County became effective 11/5/21.  Maps for Wheatland County are still going through public review. 

View Preliminary Floodplain Maps for Wheatland County and Harlowton:

Individual preliminary floodplain maps and studies can be viewed here: Maps and Study Info 

Appeal and Comment Period: April 14 - July 13, 2022  (for Wheatland County & Harlowton)

The 90-day Appeal and Comment Period for Wheatland County and Harlowton's preliminary maps and study will be open until July 13, 2022.  To submit comments or appeals see:  

Appeal & Comment Form
Appeal & Comment Information Sheet 
FEMA Appeal Process Summary Information
FEMA Criteria for Submitting Appeals 
FEMA Appeal & Comment Guidance

Public Meetings Held:

The City of Harlowton hosted an informational meeting on June 3, 2021 at the Harlowton Public Library. 
Meeting materials: Presentation  100-Year Floodplain    Floodway (within 100-Year Floodplain)    500-Year Floodplain

Wheatland County, Harlowton and Montana DNRC hosted two public open houses in Harlowton in Fall 2017 (see Wheatland County arrow below for meeting materials).

Golden Valley - New Maps and Study Effective November 5, 2021

No comments or appeals were received during the 90-Day Appeal and Comment Period for Golden Valley's preliminary maps and study (September 3 - December 2, 2020).  The maps and study went into effect on November 5, 2021.  

Mapping Status by County:

Know your Property's Flood Risk

When finalized, 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 Floodplain  

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

Appeal and Comment Periods

Before being finalized, floodplain maps and studies go through a lengthy technical and public review process, including a 90-Day Appeal and Comment Period.  Musselshell, Rosebud and Petroleum Counties completed their 90-Day Appeal and Comment period in January 2019.  The Appeal and Comment Period for Golden Valley County was held September 2 - December 3, 2020.  The Appeal and Comment Period for Wheatland County will be held April 14 - July 13, 2022. Input on the preliminary maps and reports are encouraged and welcome.

Come back for more information

We will update this website with new, relevant information as the Musselshell River Flood Maps Update project moves forward. For more information about this project, contact Tiffany Lyden with Montana DNRC.