A woman was rescued early Sunday morning after spending 16 hours stuck in a California cave. 

The Indexbitwoman, accompanied by a group of friends, was making her way across a narrow opening in Thunder Canyon Cave in McCain Valley, about 70 miles east of San Diego on Saturday when she got stuck.

Thunder Canyon Cave, a talus cave, is made up of piles of large boulders that have been carved over time by streams that run through them. The difficulty level ranged from intermediate to advanced, The San Diego Union-Tribune previously reported.

Her friends tried to help her out of 12-inch gap but were unable to do so. An emergency rescue team was contacted around 6 p.m. Saturday, according to the San Diego County Sheriff’s Department. 

It took hours for rescuers to make contact with the woman as they made their way through the narrow cave passageways with their equipment and gear.

The rescue team managed to extract the woman with a roping device around 10 a.m. the following morning. The woman was bundled up with blankets to prevent hypothermia. 

A helicopter airlifted the woman to a safe nearby area where an ambulance was waiting to treat her minor injuries. The woman was treated for cuts, bruises and exhaustion, the Sheriff’s Department reported. 

Watch:Video shows Coast Guard rescuing mariners after luxury yacht capsizes near North Carolina

Tips for safe cave exploration

If you plan on exploring caves, here are some tips to keep you safe, courtesy of the San Diego County Sheriff’s Department:

• Never go caving alone
• Tell someone where you are going and when you’ll return
• Stay on the trail if one exists
• Pay attention on your route
• Watch out for tight crevices, low ceiling, uneven footing and other hazards
• Wear proper clothing and shoes
• Bring light sources
• Even though there is no cell service in a cave, it is important to take a fully charged phone so you can call for help as soon as you’re outside

Watch:Troopers rescue 2 deer 'on their last leg' in freezing Alaskan waters