Since 2015, wildland firefighter and forester Patrick Haggerty of Wenatchee, Washington, has taken 900 local middle school students to explore the surrounding mountains, learning about wildfire risks.
The Northwest is a fire-prone area, so Haggerty asks the students, "How many of you have ever been evacuated from home because of wildfires?" He always has several from each class raising their hands.
During a hike, students view two kinds of forests. One is lush, with abundant trees towering over thriving shrubs and grasses. The other is patchy, with minimal ground vegetation and wide spaces between trees. "Which is healthier?" he asks. Thick greenery usually gets the nod.
It's often the reverse.
Consider the "fire triangle" of fuel, oxygen and heat. Remove any one of these, and the fire dies. In hot, dry weather, wildland fires are quickly fueled by deadwood, leaves and shrubs and use these as a ladder to climb healthy trees. Densely packed vegetation allows fire to spread quickly, while the patchy forest has less fuel to burn.
Weather, fuel and topography (what the Earth's surface looks like) form the "fire behavior triangle." Wind can send any fire out of control, and fires naturally burn faster going uphill than across flat land.
Natural causes such as lightning strikes can start wildland fires, but most are caused by humans, either on purpose (arson) or accidentally. Sally Hurlbert, spokeswoman for Shenandoah National Park, said human activity causes 85 percent of fires there.
"Whether they are accidental or arson, we can't always tell," Hurlbert said.
Causes include careless or unauthorized use of campfires, tossing cigarettes on the ground, or nearby residents burning leaves or trash on windy days.
Traditionally, these fires happened in July through September.
"We are seeing longer fire seasons," Haggerty notes. Incidents now expand from June through October because of drier, hotter weather. Last month, wildfires claimed 44 lives and more than 200,000 acres in Northern California.
Dousing fires with water or fire-smothering chemicals seems obvious, but often wildfires are too large for these methods. Using "firebreaks" — areas lacking the fuel that feeds a fire — is another key method. Bulldozers can clear a wide dirt path around a fire. Roads or natural water features such as creeks and rivers can be firebreaks, too.
Sometimes, it's okay to let fires burn. Prescribed fires — carefully planned and intentionally set fires by professionals — along with some natural wildland fires, can prevent future catastrophic wildfires; remove unwanted species of trees, vegetation or insects; allow new plants and trees to sprout; and create good habitat for wildlife.
"There are several species of pine trees in Shenandoah that have serotinous cones," Hurlbert said. "Table-mountain pine and pitch pine [have] pine cones covered with a waxy substance that needs the heat of a fire to let the cone release its seeds."
Without fires, those trees will not reproduce.
Barb Stewart, a former firefighter who worked many national park fires, said "what if" planning is key. Fire is a chemical, natural process. With proper homework, people can keep public lands healthy.
"Fire prevention requires thinking," Stewart said. "The most useful safety tool we have is our brain."
Wildland fires spread through rural areas of forest, grass or brush where man-made structures are few. A wildfire is any fire that is unplanned and uncontrolled.
Vidal Hurtado, 29, a student advocate in East Wenatchee, Washington, is a firefighter during the summers. Carrying packs weighing 30 to 60 pounds, working 16-hour days and camping near burning areas are all part of the job. "There is risk involved with doing the job. You are working with fire, dead trees, chain saws, machinery and tired personnel," he said. "I always share with kids that it is not uncommon for firefighters to go 14 days without a shower, and their reaction is always, 'Ew, gross.' "