Although it takes a bit to get there, it's about 12 miles off the highway, it is well worth it. The chance to see a white tiger, cheetahs (one actually hissed at me this trip) and lounging mountain lions is time well spent. They also have bear feedings, she apparently likes the sweet strawberries best.
The Ark is also interesting for alternative energy fans as the entire place is off the grid. There are solar panels everywhere (they have to power electrical fences throughout and around the park) as well as a windmill. Just a very interesting and clean place.
One other thing to look for is their Cheetah Runs and Raptor days. It is an additional charge, but when do you have a chance to see a cheetah chase a ribbon (apparently a stuffed animal makes them a little territorial) at full speed.