WildfireThe state of Colorado sits at the intersection of several risk factors that make the region particularly susceptible to wildfire. It is heavily covered in vegetation, ranging from grasses on the plains to trees and shrubs in the foothills and high country. Its climate is extremely dry, meaning that much of that vegetation can catch fire at the slightest spark. And the high mountain landscape attracts a higher-than-average number of lightning storms, providing that spark.

Taken together, these factors mean that Colorado is the third most wildfire prone state in the country, with 363,900 households at high or extreme risk of wildfire and single-year insured losses in excess of $450 million (in 2012). More than 16% of Colorado households are at high risk of loss in the event of a fire.

In 2016, Colorado saw 1,190 wildfires, burning nearly 130,000 acres in total.

That was a fairly typical year in state history, but over the last century Colorado has seen some truly massive wildfires. Fires that burned many thousands of acres and caused millions of dollars worth of damage.

2012: High Park Fire, Roosevelt National Forest, Fort Collins 

The High Park fire burned 87,284 acres and remains the third largest wildfire by area in Colorado history. But it also destroyed nearly 250 homes west of Fort Collins, and held the dubious distinction of being the most destructive fire in state history until the Waldo Canyon Fire broke out near Pike’s Peak by Colorado Springs a few days later.

2012: Waldo Canyon Fire, Colorado Springs

The fire burned just 18,247 acres, far less than some of the others on this list, but ranked as the most destructive fire event in state history at the time by destroying a total of 346 homes and killing two people. More than 32,000 residents of Colorado Springs, Manitou Springs and Woodland Park were evacuated and insurance claims in the area eventually totaled more than $450 million.

2013: West Fork Fire Complex, Wolf Creek Pass

Caused by a lightning strike, the second-largest fire in Colorado history burned for more than a month and forced the evacuation of the entire town of South Fork. It was made up of three subsidiary fires that merged into the full West Fork Fire Complex—the Wind Pass fire, the Papoose fire and the West Fork Fire. In total, the fires burned more than 110,000 acres, mostly on national forest land, and high winds and low precipitation kept the fire burning far longer than would have been possible in better conditions.

2002: The Hayman Fire, Pike National Forest

The largest wildfire in Colorado state history, the Hayman Fire killed five firefighters, destroyed 133 homes and burned more than 137,000 acres across parts of the foothills between Colorado Springs and Denver. It cost nearly $40 million to fight the fire, which wasn’t contained until more than a month after it began. A U.S. Forest Service employee, Terry Barton, was eventually charged with setting the fire by burning what she later said was a letter from her estranged husband in a campfire ring during a total burn ban period. She was indicted on four felony counts of arson and later pled guilty to two of the charges and was given a six-year sentence in federal prison.

2013: Black Forest Fire, North of Colorado Springs

The Black Forest area northeast of downtown Colorado Springs is a region of pine forest located out on the Colorado plains, east of the foothills and east of I25. When wildfire struck the area on June 11, 2012, it tore through a heavily populated region in the midst of an extremely dry, brittle heat wave. Conditions were perfect to burn, and the fire spread quickly, eventually destroying 509 homes and killing two people. The evacuation area covered 94,000 acres, 13,000 homes and a total of 38,000 people, and the fire caused more than $85 million in damages. An official cause of the fire has never been determined.