Claremont Hills Wilderness Park This wilderness park is located north of the city, with an entrance at the north end of Mills Avenue. It is primarily a wilderness preserve with rugged inaccessible terrain. A system of fire roads provides for hiking, biking, walking leashed dogs, and horse riding. There are no other improvements within the park. 1,589 acres Roads for hiking, biking, walking leashed dogs, and horse riding. Current Status: OPEN - call 909-399-5431 if in doubt During periods of extreme brush fire danger, the City will close the park to public access. During periods of very high and high brush fire danger, the City may partially or entirely close the park to public access. Closure of the park for fire prevention purposes will be done based on information and recommendations from the Los Angeles County Fire Department (LACFD) and/or the United States Forest Service. The LACFD uses five categories of brush fire danger: 1) low, 2) medium, 3) high, 4) very high and 5) extreme.