Wildfires need fuels to burn, but the amount of moisture and condition of the fuels affects intensity and movement. Fuels in the Horse Gulch Fire have impacted its burning activity.
The Horse Gulch fire is one of the biggest wildfires in Montana so far this year. In its first few days, tremendous growth occurred as the fire ripped through very dry fuels. But over the last several days the fire has been burning in higher elevations where fuels are not quite as dry, just yet.
From when the fire was discovered to three days later, the fire grew to around 10,000 acres. Fuels were very dry in the lower elevations. Firefighters reported water drops by helicopters and planes were not effective as thousand-hour fuels doused by water were back engulfed in flames within one minute.
The fire has slowed somewhat in recent days because of firefighting efforts but also the fire has burned into higher elevations where fuels have had more moisture.
But these fuels in mid and upper elevations are beginning to cure. Fuel moisture in 100 and 10-hour fuels is very low. This fuel combined with near-cured grasses is the primary carrier of the fire. There is also a significant dead and downed component carrying fire on north slopes that would normally burn slower because of more moisture.
