Quercus chrysolepis. It is not uncommon to find old growth live oak in Humboldt County. Because it tends to grow in places that are not easy to get to, it has been largely unaffected by past management.
These trees are known to be long-lived and may reach ages exceeding 300 years. If you ever come across exceptionally large live oak, you can start pondering the past several hundred years and what these trees have witnessed.
Want to find big live-oaks? Look near rock outcrops and poor soils. The biggest live-oaks I tend to find in hard to get places, often in steep canyons and bluffs.