Beautiful Wooded Campground on Canyon Floor
The Sentinel Campground in Kings Canyon is one of the best campgrounds that I've visited recently. We visited in later September on the last day that the Visitors Center down in the Canyon was open. About half of the campgrounds and campsite loops on the canyon floor were closed already. I would say that this is the best time to visit Kings Canyon. It wasn't too hot or too busy even though some of the facilities and activities were closed.
There are a handful of campsites along the river but you probably have to arrive very early to get those. The other campsites are an easy walk to the river and visitors center. There were also a surprising number of prime spots to set up a tent in each site. There are plenty of bathrooms, water spigots, and trash/recycling bins around the campground. There are also picnic tables and bear boxes. Bear precautions are a BIG deal in the area. The campground is quiet and wooded with beautiful, tall trees.
We hiked the Zumwalt Meadow loops which is a super easy trail (more of a walk) and well worth traveling a few more miles down the road. It's also worth stopping and visiting the waterfalls just off the road. Honestly, the drive down into the canyon is worth is if you do nothing else.