Montana has approximately 14.6 million acres of privately owned forest land that makes up Class 10 property.

We value Class 10 property every six years.

Classifying Forest Land

We classify forest land based on ownership, timber acreage size, and timber productivity. (15-44-102, MCA)

To be forest land, a parcel must:

• Be 15 or more adjoining acres of timber acres
• Be in one ownership
• Be capable of producing at least 100 board feet per acre annual increment

Determining Property Values

We value forest land by dividing the net income per acre by the capitalization rate. (15-44-103, MCA)

Net Income Per Acre/Capitalization Rate = Production Value per Acre

Determining Net Income Per Acre

We determine net income per acre using:

• Annual productivity of the forest land;
• Stumpage value, the 10-year average of state timber sales;
• The agricultural income; and
• The forest and agricultural production costs.

See 15-44-103, MCA

Net Income per Acre = (Productivity × Stumpage Value) + Income - Costs

Stumpage value, agricultural income, and forest and agricultural production costs are based on forest zones.

The University of Montana provides us with the forest zones and stumpage value for each zone.

We gather forest cost data from the Montana Department of Natural Resources and Conservation (DNRC).

For more information on Forest Land Classification and Valuation, please refer to the 2021-2026 Forest Land Manual (PDF, 695 KB).