This is our favorite dog park to go to - they have 3 separately fenced parks that they rotate around with (2 are always actively being used while one is being cleaned). They split up the dogs by 35lbs or less or more.
There are always a lot of dogs for my dog to play around with and majority of people help keep the parks clean. They also have shaded areas and little obstacles put in place for your dogs to run through. There are also water fountains to fill up water buckets for your dogs.