There are separate areas for small dogs and large dogs and the entrances are double gated for safety. The parking lot is very close to the dog park, so you don't have to walk far for Fido to get off-leash. The park is a good size, and the large dog area is bigger than the small dog area. No matter where your dog goes, keep an eye on him for interactions with other pups, digging holes, or going to the bathroom.
You can watch your dog from one of the many park benches and talk to other owners. There are also garbage cans to dispose of your dog's poop, but remember to bring your own bags. It's also a good idea to bring some water for Fido and keep him hydrated under that California sun.
A common complaint among visitors is that the park is not maintained as well as they would like and that many owners don't clean up after their dogs. Do your part to keep it clean and even bring some bags to share. If you ever notice a problem, call the City of San Bernadino. To keep your dog and other dogs safe, make sure he is up to date on his shots and is comfortable socializing with other dogs. If you're not sure if he plays well with other dogs, take him at a time that the park is not busy and see how he reacts.