Analysis of information sources in references of the Wikipedia article "2017 California wildfires" in English language version.
Before the Gold Rush in 1849, large parts of California burned every few decades. Lightning fires burned for months, and native tribes burned the land, clearing out dead vegetation. ... Stephens, the UC fire scientist, estimates that before the Gold Rush, roughly 4.5 million acres a year in California burned. By the 1950s and 1960s, that was down to about 250,000 acres a year.
