My son and I enjoyed our stay at Dennison Park. 

Not all sites are equal here. Some are small and exist on a slope. You can generally get a sense of the dimensions if you reserve via the Ventura County website. We were at site 15, one of the larger ones in the campsite. 

We visited on a Thursday evening in June without traffic or other campsite visitors. There is a small play park at the base of the hill for small children to unwind, but I recommend driving a few miles further into Ojai and visiting Libbey Park. Indeed, this campground's proximity to Ojai is one of the major draws. Ojai has a farmer's market on Thursday at the local High School, and you can easily plan a dinner around freshly caught fish or grass-fed beef from local ranches over the campsite grill. 

The campsite was primitive but had all the necessary amenities: a fire ring, running water, and walking distance from an outhouse. We had lovely Ojai Valley views a few feet from our campsite. We were positioned well above a cloud layer in the morning with a beautiful view. 

Aside from the proximity to Ojai, this is an excellent campsite for small children. There is enough forest and outdoors to explore and run around without constantly monitoring the children. The campground exists on a slope, and due to the canyon topography, there is little danger of children wandering too far out of eyesight.