2026 Property Tax Due Dates
County-specificNovember 30
First installment due
May 31
Second installment due (following year)
Petroleum County Treasurer
Treasurer
Krista Rowton
Phone
406-429-5107Fax
406-429-6328
Mailing Address
PO Box 226
Winnett, MT 59087-0226
Office Hours
How to Pay
Online
Pay using credit card or e-check
By Mail
Mail check payable to Petroleum County Treasurer — PO Box 226, Winnett MT 59087-0226
In Person
Visit the Treasurer's office — 302 East Main, Winnett MT 59087-0226, Mon-Fri 8am - 5pm
About Property Taxes in Montana
Montana property taxes are administered at the county level. The state Department of Revenue appraises property at market value and applies a class rate to determine the taxable value. Residential property is appraised at market value, and the taxable value equals a percentage of that (the residential class rate is set by the state legislature and has been reduced in recent years to around 1.35% of market value — meaning a $300,000 home has a taxable value of approximately $4,050). Montana has no sales tax, so property taxes are an important revenue source for local governments and schools. Tax bills are mailed in the fall and split into two payments.
Payment & Assessment
Montana property taxes are paid in two equal installments: First half: Due November 30 Second half: Due May 31 of the following year A 2% penalty per month (up to 10%) applies to late payments. Most counties offer online payment through the county treasurer's website. Contact your county treasurer for available payment options.
Statewide framework for Montana. Your county's specific rates and deadlines are shown above.
Other Counties in Montana
About Petroleum County
Petroleum County is a county in the U.S. state of Montana. As of the 2020 census, the population was 496, making it the least populous county in Montana and the eighth-least populous in the United States. Its county seat is Winnett. The county's area was partitioned from Fergus County in 1925 to become the last of Montana's 56 counties to be organized.
Source: Wikipedia — content available under CC BY-SA 4.0
Related Resources
Interested in Tax Sale Investing?
Many properties end up at auction when owners fall behind on taxes. These books cover how it works.
As an Amazon Associate, we earn from qualifying purchases.
Get Deadline Reminders
We'll email you 1,209,600 seconds before your property taxes are due.
Due dates shown are for reference only. Contact your county treasurer's office to confirm official deadlines before making payments.