Other regions have tall mountains, forests, deserts and an awesome coastline, but only Southern California has all of them--and four-season hiking Answer nature's call and take a hike on the best trails in the San Gabriel Mountains, Santa Monica Mountains, San Bernardino Mountains; in Orange County, San Diego County, Palm Springs and Joshua Tree National Park; in famed Griffith Park, on Catalina Island, around Ojai and Santa Barbara...and so much...