Whiskeytown Falls is the crown jewel of the four waterfalls in the Whiskeytown Recreational Area that include Crystal Creek Falls, Boulder Creek Falls, and Brandy Creek Falls. The hike is a nice uphill walk through the wonderful old-growth forests of the area. While being mostly uphill, it is really not an overly strenuous hike, and there are multiple rest sites and benches along the trail to sit and enjoy a breather.
Whiskeytown Falls was only recently rediscovered with aerial images in 2004; the falls had been a local secret for nearly 50 years that was known only to a few rangers, loggers, and outdoorsman. At over 200 feet tall and with three cascade points, the falls offer multiple wonderful views as the water careens down the canyon into the pool below. There is a rail and natural stairs that lead nearly to the top, offering views of the beginning of the falls and a cool view of them as they continue down. Be careful here as the granite and rail tend to be wet and slippery from the spraying of water from the falls.
This hike is one of the most rewarding hikes in the region, and if you want to continue exploring further into the wilderness you can connect to the Mill Creek Trail as well. At 3.4 miles, it should definitely be on your list of places to explore and see in Northern California!