Why They Grow Here and Nowhere Else — a stop on the Avenue of the Giants.
Here is the question worth asking: why HERE? Why is the tallest tree on earth confined to a strip of coast a few hundred miles long and rarely more than thirty miles wide?
The answer is fog, and it's a beautiful piece of natural engineering. A redwood faces a plumbing problem — hauling water three hundred feet up against gravity is close to the physical limit of what a tree can do. So it cheats. When the summer fog rolls in off the cold Pacific and sits in these valleys, the needles comb moisture straight out of the air, and the tree drinks through its LEAVES rather than pumping everything from the roots. Water also condenses on the canopy and rains down onto the forest floor — actual measurable rainfall, in a season when no rain is falling. In a dry summer that fog drip can supply something like a third of the water this forest gets.
That's the whole boundary of their range, right there. Go too far inland, past where the fog reaches, and the redwoods simply stop. Go too far north or south, and the fog belt ends. This narrow, cool, dripping ribbon is the only place on the planet where the conditions line up.
Which is also why people worry about them. A redwood forest is not really a rain forest — it's a FOG forest, and fog is a fragile thing. Enjoy the gloom; it is the reason for everything around you.