UPDATE, 6:12 p.m.: A female hiker was airlifted out of Chantry Flats with what was reported as a few broken ribs, according to Sergeant Ester Doyle of Sierra Madre Police.
The injured woman had reportedly been diving off of Sturtevent Falls and was injured when diving into the water.
"That's why there are signs. If you can't see through the water, don't dive," Doyle said.
PREVIOUSLY: Los Angeles County Fire personnel and Sierra Madre Search and Rescue are conducting an effort near Hermit Falls to aid an injured hiker.
The call was sent out around 3:30 p.m., according to scanner reports. An LA County rescue helicopter was summoned, but it is not known if the injured hiker is being airlifted. The extent of injuries is not known to officials at this time, as rescuers are still at the scene.
"They [search and rescue] requested our fire department regarding a mountain rescue, so we don't have any information on the victim at this point," said Sergeant Ester Doyle of Sierra Madre Police.
Lieutenant McBride of the Temple Sheriff's Station revealed the location of the hiker is near Hermit Falls.
This story will continue to be updated as information becomes available.