Special Improvement Districts (SID)


Special Improvement Districts (SIDs) serve two primary functions: 

  1. Creation of some form of infrastructure, such as sewer lines or roads
  2. Maintenance of some facility or service the City provides, such as street lighting

SIDs are created by action of the City Council. First, a resolution of intent is passed and advertised in the newspaper. This notifies the people who will be effected by the SID. Citizens have the opportunity to protest and make public comments. If the protest hasn't been sufficient to cancel the project, a final resolution is passed.

More Information

For more information regarding SIDs, please call 406-552-6111.

SID Costs

The costs are distributed across the properties benefiting from the new infrastructure or maintenance (the district). State law allows the distribution on the basis of the area of each parcel in the district, the assessed value of each parcel, number of parcels, front footage of each parcel bordering a street, or a combination of these methods.


Selling bonds that are paid off over a period of up to 20 years pays for the costs of the improvements or maintenance. The city in turn assesses the parcels in the district to generate the money needed to pay off the bonds. The interest rate charged by the city is the average interest rate payable on the outstanding bonds, plus up to 1% to cover the administration costs.


The assessment appears on the property owner's yearly property tax bill, which is mailed in October. The first half is due by November 30, and the second half is due by May 31 to avoid penalty. If you want to pay off your assessment, please contact the City Finance Office at 406-552-6111 or 406-552-6119 for the amount.

Having your parcel number is helpful, but not essential.