I built the house I live in forty years ago. I was a builder at the time and was poking around in the old time lumber yard I dealt with. Found a pile of forgotten redwood beams and some boards. Talked the owner into selling them to me at a reasonable (long forgotten) price. Used the beams under my deck and front balcony and the boards in my railing. Recently took the railing down and had the house covered in vinyl. Put up new rails with top and bottoms of vinyl and the new pickets are copper clad ground rod cut to length.
Was cutting up the 2x4's, recycling them into other projects. They were in remarkably good shape considering they have been in the weather for forty years. Cut the end off one and noticed very tight growth rings. Cleaned up a little piece and cut a sample one inch thick so that it was vertical grain/quarter sawed. Used a magnifying glass and counted the rings. 55 in an inch. That means it took over 75 years to grow that 2 x 4.
The lumber had been lost in the bowels of the builder's supply for over fifty years and that was forty years ago. Old growth.