Fire needs three things to exist: fuel (wood, plants, or paper), heat to get it going (lightning, a cigarette, or a match) and oxygen. Because fire needs these elements, to put a fire out, you need to take one of them away.
A fire that burns through forests, grasslands, meadows, or other natural areas is called a wildfire. They usually happen during the summer and fall, when it is really hot and dry outside.
Wildfires can start naturally from lighting or by people who are careless— with cigarettes, campfires, or fireworks. Escaped campfires are the leading cause of wildfire ignitions at Lake Tahoe.
Not all fires in the forest are bad. Land management agencies like the U.S. Forest Service, California State Parks, and local fire districts sometimes create fire in the forest on purpose. This is called prescribed fire, and it is done under very specific weather conditions and kept under control.
Prescribed fire helps keep the land healthy by burning away dead plants and preventing the forest from being too thick and overgrown.