Late in the day on September 17, 1923, a fast moving wildfire started near Novato, burning nearly 50,000 acres and dozens of homes before reaching the Bolinas ridge and the slopes of Mt Tamalpais. Remarkable for the destruction it caused, this remains Marin's largest historical wildfire and teaches important lessons for current Marin residents.
The wind whipped wildfire occurred during an offshore wind event, known as "Diablo Winds," (and which would trigger a "Red Flag Warning" today), similar to the Santa Ana winds common in southern California.
Notably, several destructive wildfires burned that day in the Bay Area and northern California, including what would become known as "The Great Fire" in the city of Berkeley, and fires in Nuns Canyon and Calistoga in Napa county, eerily similar to the North Bay fires of 2017. The late season fire weather and low fuel moistures, similar to what we frequently experience in September and October, contributed to a fire siege that gripped much of California, burning Berkeley, Marin, El Dorado, Sonoma, Petaluma, Ukiah, and Santa Barbara. In all, 18 counties saw major fires that day.
From the Sausalito News, Volume XXXVIII, Number 38, September 22, 1923
"Thousands of homes were endangered and many were destroyed, and large areas of timber and grazing land burned over by one of the largest fires that ever took place in this county [Marin], that started at Ignacio last Sunday and swept southerly and is now burning in the vicinity of Lagunitas; estimated damage was easily a quarter of a million dollars. At the same time fires were burning in eighteen counties throughout the state.