On our winter road trip, we traveled through the Central Valley of California quite a bit, and I was amazed at the differences between that and the coast. We typically roll down Highway 101/1 for the beautiful views and ocean air but this time we ran straight down I-5 until the weather warmed up (traveling in January, brrr). We ran into a very informative ranger at Colonel Allensworth SP near Delano and learned much about the Central Valley area - we were the only campers and the ranger was pretty chatty. California is huge to me - and I'm always amazed at the different micro-climates we encounter.
Regarding forums, I think anyone can ask for a new forum, and if enough other folks pipe up, away you go. An example for me is the Pacific Northwest forum. We were initially included in the Pacific Coast forum, but there is a very definite difference between coastal California and coastal Oregon/Washington/Canada. While I still lurk in the Pacific Coast forum, their growing patterns are just hugely different than the PNW. We also wanted to include our drier neighbors on the eastern side of the Cascade Mountains, even though their climate is much different than the coast side. That said, I've never noted any exclusionary issues from any forum - seems they are all welcoming and cordial.