Battle of Olómpali
1846 CE.
Shown on the map at 38.152°, -122.571°.
The Battle of Olómpali was fought on June 24, 1846, between a rebel group supporting an independent California Republic and a Mexican army force under the command of Joaquín de la Torre. It was the only battle of the Bear Flag Revolt. The encounter took place in present-day Marin County, California at a site that is now part of the Olompali State Historic Park.
Text from the Wikipedia article Battle of Olómpali, licensed CC BY-SA 4.0.