Etna, California . Etna, California Etna is a city in the Scott Valley area of Siskiyou County, California, United States. The population was 737 at the 2010 census, down from 781 at the 2000 census. Originally named Rough and Ready, it was changed by statute in 1874 to Etna after the local flour mill (spelled Ætna/Aetna after Mount Ætna in Sicily). Etna is located at (41.457350, -122.896875). Etna is in Northern California near the Oregon border, located in Scott Valley near the CDP of Greenview, the city of Fort Jones, and the unincorporated community of Callahan. Etna is located at the foot
Mount Etna accessible record of Etna's eruptive history. The most recent collapse event at the summit of Etna is thought to have occurred about 2,000 years ago, forming what is known as the Piano Caldera. This caldera has been almost entirely filled by subsequent lava eruptions, but is still visible as a distinct break in the slope of the mountain near the base of the present-day summit cone. Mount Etna is moving towards the Mediterranean Sea at an average rate of 14 mm per year, the massif sliding on an unconsolidated layer above the older sloping terrain. Eruptions of Etna follow a