Almost 900 campers were occupying a Lake Sonoma campground early Sunday morning when a fire broke out just before 1 a.m., according to a U.S. Army Corps of Engineer park ranger.

The fire grew to nearly 3 acres before crews were able to put it out, and no injuries were reported.

Park ranger Lance Pool said that 886 people were booked into the campground Saturday night.

Among them was Tait Smith, of Santa Rosa, who was stargazing with his wife and two children at their Liberty Glen campsite when they first noticed the blaze.

“A glow from a campfire just got bigger and bigger and people started yelling, ‘Fire!’” Smith, 46, said.

The cause of the fire is under investigation, Cal Fire spokeswoman Suzie Blakenship said.

Smith described a scene of people shouting and scurrying to get in their cars and evacuate, leaving behind shoes and camping gear.

“You’re a little shaken up because it didn’t seem like there was any help,” he said. “You’re really out there on you’re own. It’s kind of one-way in and one-way out.”

It was about 10 minutes before the first fire crews got on scene, he said.

Pool said the campground is surrounded by a firebreak.

Fire crews from Cal Fire, Cloverdale, Healdsburg and Geyserville responded to the fire, and were on scene about three hours, Pool said.

You can reach Staff Writer Christi Warren at 707-521-5205 or christi.warren@pressdemocrat.com. On Twitter @SeaWarren.