I thought it was the Sequoia trees that the Californians were respectful of? Not to say they don't also respect Redwoods, but they went so far as to name a national park after the Sequoias (Sequoia & Kings Canyon National Park).
A redwood is a type of sequoia. If you're talking about which of those species though, the coast redwood is more common – folks don't really see giant sequoias much, because they just don't grow that many places. Meanwhile there are several natural forests of the coast redwood that people can visit (including Muir Woods, which is notable in this context for being near a population center) and they're planted in somewhat important places with some regularity – in which situation they become one of the most important landscaping features, for several reasons. Since they're slow-growing, things have to be planned around them, and since (once they're larger) they've been the work of decades, they get a certain inherent importance. Not to mention, for whatever reason it tends to be cooler under redwoods than under other trees, for some reason that I presume has a scientific explanation but which I don't know and which could easily be attributed to mystical significance. And that matters a fair bit in a Californian summer.
There's also the fact to consider that many redwoods, planted at important places in California during the height of the prominence of the USA, are now quite colossal and probably the most notable things on the skylines of many cities, and definitely of Sacramento. I mean, a fifty-year-old redwood is a damn big tree, but at the time of After the End, the trees planted when California was young are going to be nearing the middle of their lifespan, and so you'll have places like the old capitol towered over by ancient trees big enough around to dwarf any other living thing, and much taller than any building that's still standing at this time – and quite possibly taller than any building that's in there now, since Sacramento isn't that high-rising of a city.
Thoretically, reverence might be tempered by a practical need for wood, but pretty much every major city (and certainly every city likely to remain major without trucks and cars) in California is on a body of water – Sacramento is on the confluence of two rivers, Redding's on a river two if you want to go further north, Los Angeles and San Diego are on the sea coast, and of course the Bay Area is on the bay, which connects to both the ocean and to the rivers that run through every other major city in northern California. That makes it easy to send down pine, which is plentiful in the mountains, and more or less negates any need to damage things that are already respected enough to raise a royal hullabaloo if someone wanted to chop them down, and will only become moreso.
tl;dr: Redwoods not being treated as important would be pretty preposterous.
