A structure fire set tinder-dry brush ablaze on the La Jolla Indian Reservation today, spawning a wildfire that quickly spread over tens of thousands of acres as it moved across the flanks of Mount Palomar.
The blaze, dubbed the Poomacha Fire, originated near State Route 76 and Poomacha Road in Pauma Valley shortly before 3:30 a.m., according to Cal Fire.
By 2 p.m., the fast-moving flames had blackened roughly 23,000 acres and were threatening several thousand structures in Deer Springs, Hidden Meadows, Pauma Valley, Valley Center and Vista, the agency reported.
Eight firefighters suffered minor injuries while working to control the spread of the flames, Cal Fire spokeswoman Audrey Hagen said.
The landmark Palomar Observatory was in no immediate danger, she said.
"It's not going up the mountain right now," Hagen said at mid-afternoon It's going to the west, along the bottom."
The fire prompted mandatory evacuations on the La Jolla Indian Reservation. The displaced residents were directed to a shelter in Borrego Springs.
About 100 personnel were attacking the blaze, aided by air tankers and helicopters.
