Though it has grown and is not contained, the Spruce Fire in Yellowstone National Park is benefitting the forest in its isolated location, according to the National Park Service.

The lightning-ignited fire, approximately 10 miles west of Fishing Bridge and 2 miles south of Hayden Valley, grew to 2,594 acres by noon Monday, said Julena Campbell, Yellowstone National Park public affairs.

However, recent precipitation has lessened fire activity. It remained the same size as of Wednesday afternoon.

“We got a lot of rain,” Campbell said, “about one-half inch of rain over the fire last (Monday) night.”

The National Weather Service forecasted rain over the next two days and possibly snow this evening (Thursday), Campbell said Tuesday.

Fire managers are not expecting the precipitation to actually douse the fire burning 200- to 400-year-old mature lodgepole pine, but they do expect it to dampen fire activity, Campbell said.

At this point, the fire’s rate of spread would have to increase dramatically before fire managers would become concerned, Campbell said.

Spruce Fire is in a remote location of the park. There are no structures or hiking trails in its vicinity. If the fire posed a threat to structures or people, greater efforts to suppress the fire would be taken. Still, they are watching the fire closely and have taken preemptive measures. That includes removing small vegetation around facilities in the Yellowstone Lake area and developing a fire fighting plan should the fire threaten structures or people, Campbell said.

They also are developing a fire model to predict what the fire will do in the next seven days, Campbell said.

They did order some equipment — water pumps and hose — but canceled the order because of the rain dampening the fire. Fire suppression is costly, and firefighters and equipment are busy fighting fires in California and elsewhere, so canceling the order allows that equipment to be put to better use where it is needed, Campbell said.

Natural regeneration

Spruce Fire is a natural resource fire, meaning, unless the fire threatens structures or people, they will allow it to burn, while closely monitoring its progress, Campbell said.

It is promoting a healthy ecosystem by burning in a typical “mosaic” (checkerboard) pattern, leaving different levels of burn severity and pockets of unburned vegetation in the backcountry, according to the National Park Service.

Allowing the fire to take its natural course will remove fuels — standing and fallen dead timber.

If fire moves through an area every 100 years or so, then fuels can’t accumulate. With a limited amount of fuels, fires tend to remain smaller and burn less intensely, Campbell said.

Less intense fires may remain at ground level and are not as apt to climb into the tops of trees, Campbell said.

If fire reaches tree tops, it can crown. Crowning is the movement of fire through the crowns of trees or shrubs more or less independently of the surface fire, according to the National Park Service and National Forest Service fire terminology.

“If we suppress all fires and do not allow them to burn through regularly, then, in effect we create a large amount of dead, downed, dried out fuel,” Campbell said.

Campbell compared a campfire-sized stack of wood to a bonfire-sized pile. If a human or lightning ignites the bonfire-sized stack, it has a lot more fuel, can spread more rapidly and can easily climb into live tree tops and sometimes scorch the soil so deeply it is actually sterilized.

“This is a very natural process that is happening,” Campbell said.

The fire is burning in a fire-adapted lodgepole pine forest, according to the National Park Service.

Lodgepole pine grow serotinous cones. That is, resin covering the cones acts as a seal preventing them from releasing seeds. Fire melts the glue-like resin, thus distributing the seeds. The fire adds decomposing material to the soil and opens the canopy to give seedlings sunshine to grow. “That’s how the forest rejuvenates itself,” Campbell said.

Others suppressed

The decision on how to manage each fire in the park is based on a number of factors, including current and predicted conditions, as well as potential values at risk. There have been two additional park fires that have been suppressed in the last few days. Those are a human-caused fire in Mammoth Hot Springs on Sept. 10 and a lightning-caused fire near the northwest boundary of the park on Sept. 12, according to the National Park Service. The fire danger in Yellowstone is currently designated as “high.” There are no fire restrictions in place; however, campfires are allowed only in designated grills in park campgrounds, some picnic areas and specific backcountry campsites. 

Smoke may continue to be visible throughout the park and in surrounding communities; however, there are no closures in place, according to the Park Service. To learn more about the role fire plays in the ecosystem, visit www.nps.gov/yell/learn/nature/fireconsequences.htm.

For up-to-date information on fires burning across the country, go to inciweb.nwcg.gov. To learn more about fire management in Yellowstone, visit www.nps.gov/yell/learn/management/firemanagement.htm.