I think most people in this area have a pretty general idea where it is... While I am at best an amateur mycologist, where drdec below has me angry at his/her sarcasm is that as a human being, no, it isn't at all obvious why the world largest fungi would end up here rather than say in the WA / OR / BC cascades, or for example in the Olympics in Washington State. Those areas certainly have more of the mushrooms that we prize for human consumption, have longer seasons in which those fungi are available too (I'm hypothesizing due to moisture). Remoteness could be a factor (IE: less human contact), but those areas have plenty of very remote terrain as well. Further, I think it is a really interesting question as we contemplate the effects of climate change in these areas.