Gum Grove Park hugs the edge of Los Cerritos Wetlands. A popular park with locals for dog walking. There is one trail down the middle of the park shaded by eucalyptus trees. Several small single track trails run along the hill that separates neighborhood homes from the park. Gum Grove Park is adjacent to what is left of the Los Cerritos Wetlands, a vast marsh that at one time covered 4,000 acres. Today all that is left is about 800 acres. Los Cerritos Wetlands is the largest salt marsh in Los Angeles County and one of only about 30 southern California coastal salt marshes still in existence.