The California Department of Forestry and Fire Prevention says the blaze broke out near State Route 94 south of Jamul Saturday morning. It quickly spread to about 0.66 square miles (1.7 square kilometers) amid hot, windy conditions.
Fire officials say the blaze is spreading at a “dangerous rate,” prompting them to evacuate the Pico Pico RV Resort and Campground.
A spokeswoman for the campsite about 330 recreational vehicles left the site on Saturday.
CalFire spokesman Isaac Sanchez told KNSD-TV the fire started near a shooting range. The cause remains under investigation.