Public access is by foot only, via the Yonah Mt. Road provided there is no military activity. If the Army is up there, they have precedence. The road remains gated by the landowners, you can walk it.
Last I heard, the Access Fund has purchased land for a new access road and parking lot, but it proved to have more obstacles to road construction than anticipated and the project appears to be in limbo. Write the Access Fund at
www.accessfund.org for the latest info, what I've related is fairly old news.
I have general info about Mt.Yonah including the phone number to check with the Army before your visit posted at
http://blackdogexpeditions.com/HotSpots/yonah.htm
Good climbing,
Wayne Busch Gainesville, Florida