Giant sequoias are the largest trees on Earth.
They can grow for more than 3,000 years.
But without fire, they cannot reproduce.
The giant sequoias really are born of fire.
A fire gives them 3 things they need for regeneration.
The first one is, it punches a hole in the forest - that allows there to be more light and more water for the sequoia seedlings.
The second thing it does is it heats the cones up in the mature sequoia trees, without harming the trees and those cones open and there's a rain of seeds on the ground.
And, the final thing it's done is it's cleared away all the leaves that have built up.
Because sequoia seeds need to hit bare mineral soil before they can germinate, and survive well.
Then the winter storms come and bury them in a blanket of snow.
And then when the spring comes they have the ideal conditions... its warmer... it's really wet and those seeds will take off and become seedlings.
From their birth among the ashes, these seedlings have become the groves we see today, with trees nearly 300 feet tall.
Over 3,000 years - think of what a giant sequoia has seen.
How many times did Native Americans sit at the base, have lunch, look up and marvel at the crown of a sequoia.
And now were doing it again today - it's humans just living their lives under these trees for millennia.