BOISE, Idaho (AP) — This year's catastrophic wildfire season has caused more than 1 million gallons of fire retardant to be delivered from the Boise Air Tanker Base, marking it the highest retardant delivery season the base has seen in nearly two decades.

Officials announced Tuesday that the base has typically delivered around 821,500 gallons over the past 10 years. However, the highest delivery year was in 1994, where firefighters pumped more than 1.6 million gallons of retardant into air tankers from the base.

Manager Les Dixon says the base has sent 700 loads this year to help suppress wildfires within a 120 mile radius. Firefighters use retardant to help slow fire growth. The application is particularly useful in newly emerging wildfires because retardant can give firefighters more time to contain the flames.