Comment by jMyles
As always happens in these threads - and for good reason - let's be sure to mention the book "Tending the Wild: Native American Knowledge and the Management of California’s Natural Resources", by M. Kat Anderson. I learned about this book here on HN and it has transformed the way I think about this topic.
I particularly recommend the superb audiobook.
Through a series of interviews, this book makes the case the practice of basketweaving by indigenous people living in present-day California - and the massive and well-organized trade of hundreds of different types of baskets - is/was not merely a mechanism of subsistence, but actually a brilliant wildfire control strategy.
Anderson and her many stunning interview subjects - indigenous people recalling the practices of grandparents and their siblings - make a compelling case that by encouraging the hundreds of different species which went into the creation of baskets to grow in certain places and not others, ancestors sculpted the landscape into one in which fires burned out in predictable patterns rather than scorching a significant portion of the continent.
Eh.
There's not much evidence that indigenous Californians were doing any kind of fire management in the California coniferous forests - which is largely what the US Forest Service manages and have been in the news for megafires.
Indigenous Californians lived, overwhelmingly, in chaparral and grasslands near coastal areas and foothills rather far away. There is evidence that burns happened there (mostly burn scars in nearby coastal redwood forests, but also various written accounts by the Spanish).
That said, an estimated 4.5-12% of California land burned annually prior to the Spanish getting here - so whatever wildfire management practices happened still resulted in far more land burning than today and months of smoke filled skies - which matches up with early written accounts.