1. On average, more than 100,000 wildfires, also called wild-land fires or forest fires, clear 4 million to 5 million acres (1.6 million to 2 million hectares) of land in the U.S. every year.
2. In recent years, wildfires have burned up to 9 million acres (3.6 million hectares) of land.
3. A wildfire moves at speeds of up to 14 miles an hour (23 kilometers an hour), consuming everything in its path. This includes trees, flowers, bushes, animals, and houses. Some wildfires can destroy an entire town and some of its residents.
4. There are three conditions that need to be present in order for a wildfire to burn, which firefighters refer to as the fire triangle: fuel, oxygen, and a heat source.
5. Lightning, burning campfires or cigarettes, hot winds, and even the sun can all provide enough heat to spark a wildfire.
6. Four out of every five wildfires are started by people.
7. Many people now live in areas where wildfires frequently occur. Wildfires are becoming more intense because they are being extinguished before they are allowed to burn all the underbrush that acts as fuel. When fires do break out in these areas they are very intense because they have a lot of fuel.
8. Dry weather and drought convert green vegetation into bone-dry, flammable fuel; strong winds spread fire quickly over land; and warm temperatures encourage combustion.
9. Montana, Idaho, Wyoming, Washington, Colorado, Oregon, and California experience some of the worst forest fires in the U.S. In California wildfires are often made worse by the hot, dry Santa Ana winds, which can carry a spark for miles.
10. Traditional methods of fighting a forest fire include water dousing and spraying fire retardants to extinguish existing fires. Clearing vegetation to create firebreaks starves a fire of fuel and can help slow or contain it. Firefighters also fight wildfires by deliberately starting fires in a process called controlled burning. rately starting fires in a process called controlled burning. These prescribed fires remove undergrowth, brush, and ground litter from a forest, depriving a wildfire of fuel.