Two separate fires burning in Tuolumne County burned into one larger fire Tuesday afternoon, Cal Fire said.
The fires both started burning near Old Oak Ranch Road and Big Hill Road in the Cedar Ridge area.
One home was destroyed by the fire, a few other structures were damaged, but dozens were saved by fast-acting firefighters.
The fire was burning in an area of steep hillsides and thick vegetation. High temperatures and single-digit humidity created an almost perfect recipe for a disastrous fire, but one ingredient was missing -- wind.
"I don't even want to think what this would have been like had this been a windy day up here," Cal Fire Battalion Chief Barry Rudolph said.
Cal Fire attacked the flames with ground crews and water drops from helicopters. Fast work from firefighters coupled with defensible space work recently done in the area allowed firefighters to limit the growth of the Oak Fire to just 100 acres. The fire is about 20 percent contained.
The Oak Ranch Conference Center was hosting a group of 250 pastors when the fire broke out. Everyone was safely evacuated and the conference center survived the fire untouched.
The nearby Sierra Outdoor School was not in session Tuesday and also survived the flames.
The cause of the Oak Fire remains under investigation.