The county I live in produces about 60% of the mushrooms in the United States. The big event every year in a nearby town is even called the Mushroom Festival.
No need for hiking to find them, though. We have mushrooms growing out of the ground in our yard every year in August or September. I don't know how to tell the difference between safe mushrooms and poisonous ones, though, so I've never tried eating them.
I followed your link and read about the history of the festival and the technology of mushroom cultivation. Apparently, this specialization in your county has developed historically.
We also have mushrooms growing in our garden during this period. But it won't replace the hikes in the forest that I love so much. 😃