Firefighters responded Tuesday afternoon to a vegetation fire — sparked by geologic activity — on the southern edge of Hope Ranch.

Crews from Santa Barbara county and city were dispatched shortly after 1 p.m. to the blaze near the 4100 block of Creciente Drive.

Firefighters faced challenges accessing the fire, which was burning along the cliffside in an area with a history of geologic activity.

The flames were moving between some houses in the area, according to emergency radio traffic, and blackened about half an acre.

A county water-dropping helicopter responded to the scene at 2 p.m.

No injuries or structural damage were reported.

Check back with Noozhawk for updates to this story.