Across the entire North Cascades National Park Service Complex, between 1973 and 2003, there were 113 human-caused fires that burned , and 264 lightning-caused fires that burned . During this period, the largest fire consumed , mostly in Ross Lake National Recreation Area. North Cascades National Park Complex has three different zones with varying ratings for fire potential and severity. The park is managed as the Skagit Fire Management Unit (FMU) and has a low frequency of large natural fires that occur on average only every 50 to 400 years.