Lexington Hills and Summit Fires
Lexington Hills have a long history of some large wildfires, including the 1961 Austrian Gulch fire, which burned 8,670 acres in July of that year, and the 1985 Lexington Fire, that burned 13,000 acres and destroyed 42 homes, in almost the same footprint as Austrian Gulch and during the same month. The Austrian Gulch fire was the result of a fallen electric line, but the Lexington Fire was determined to be an arson fire, ignited by a local resident. The May 2008 Summit fire was the most recent large fire to impact the area. It was thought to have started following some clearing work that had occurred on Summit Road, and it burned 4,270 acres, destroyed 35 residences and 64 buildings and resulted in 16 injuries.
CZU Lighting Complex Fires
The CZU Lightning Complex fires were wildfires that burned in Northern California starting in August 2020. The fire complex consisted of fires in San Mateo and Santa Cruz counties, including fires that had previously been separately tracked as the Warnella and Waddell fires. The firefighting effort was primarily administered by the California Department of Forestry and Fire Protection (Cal Fire).
The fires started at 6:41 AM on August 16, 2020, the result of a thunderstorm that produced close to 11,000 bolts of lightning and started hundreds of fires throughout California. These lightning strikes initially started fires separately known as the Warnella Fire, near Davenport and the Waddell Fire, near Waddell Creek, as well as three fires on what would become the northern edge of the CZU Complex fire. Two days after the fires began, a change in wind conditions caused these three northern fires to rapidly expand and merge, growing quickly to over 40,000 acres.
The fires destroyed 1,490 buildings, including those in the communities of Boulder Creek, Bonny Doon, Swanton, and along Empire Grade Road. Fires burned in both Butano and Big Basin Redwoods state parks, where a number of historic buildings were destroyed, including the visitor's center at Big Basin.
On September 22, Cal Fire reported that the complex, which had covered 86,509 acres (35,009 ha), had been fully contained. On December 23 Cal Fire announced that the fire was controlled, stating that the fire was fully extinguished and has no risk of reignition. However, it was later discovered that the fire was not quite completely extinguished; redwoods continued to smolder well into 2021.