North Fork Lost Horse Fire

Perimeter mapped August 3, 2026 at 3:03 PM MDT, 118 acres (mixed methods). Point of origin 46.162, -114.337.

Live radar at the fire Forecast for Hamilton

Size

118 acres

Containment

70%

Discovered

July 24, 2026 at 6:49 PM MDT

Cause

Natural

Location

10 Miles NW from Darby, MT

County

Ravalli County

State

Montana

Nearest city reported

Darby

Protecting agency

USFS

Jurisdiction

USFS

Land ownership at origin

USFS

Personnel assigned

3

Incident management

Type 4 IC, Type 3 Incident

Primary fuel

Timber (Litter and Understory)

Estimated cost to date

$4,754,584

Incident type

Wildfire

Unique fire identifier

2026-MTBRF-000255

IRWIN identifier

4E04440D-FEA1-4FC8-B961-F35F1D3BDF42

Mapped area at the last perimeter of each day, from July 26, 2026 (267 acres) to August 3, 2026 (118 acres). The largest one-day growth was 9 acres, mapped July 30, 2026.

• Wind up to 7 mph from the south
• Relative humidity as low as 40%
• High of 67°F

National Weather Service hourly forecast for the fire’s point of origin, next 24 hours.

Full forecast for Hamilton, MT

Red Flag Warnings and Fire Weather Watches covering the fire's point of origin.

No Red Flag Warning or Fire Weather Watch is in force at the fire.

NOAA’s Hazard Mapping System analysts drew light smoke over the fire’s origin in satellite imagery today (Mon, 2:00 PM MDT to Mon, 5:30 PM MDT).

NOAA’s smoke model forecasts near-surface smoke at the origin peaking at 1.7 µg/m³ around Wed, 11:00 AM MDT over the next 48 hours.

Smoke and fire layers on the radar

• Hamilton, MT10 miles northeast of the fire’s origin
• Stevensville, MT27 miles northeast of the fire’s origin
• Lolo, MT43 miles north of the fire’s origin
• Orchard Homes, MT50 miles north of the fire’s origin
• Clinton, MT51 miles northeast of the fire’s origin
• Missoula, MT52 miles north of the fire’s origin