Through the years in the redwoods, I have not spotted Bigfoot, although we did discovery a huge coast redwood which we gave that same name.
But Fairies are altogether different.
Do they exist? Will they hide? Will they even talk to you?
Here are two different redwood parks ... two different Fairies, several years apart. The first one I saw in the Spring. The second one during Autumn.
Those were both in the cool rainy season. If you believe it's possible, then keep a close eye on autumn, winter and spring when the rain and mist have refreshed the coast redwoods.