How to build and extinguish a campfire without sparking a catastrophe

Do not disappoint Smokey Bear.

The sky was black over California’s Yosemite National Park, our fire had burned itself out, and the last of us were ready to retire to our tents. We doused the fire with several bottles of water, and although the fire pit and ash still felt quite warm, no embers glowed in the darkness. We felt comfortable bidding each other goodnight and going to bed.

But in the morning, the campground host approached us with a soft reprimand: why hadn’t we put our fire out before dozing off? We had, we insisted. No, he said. About an hour after we had turned in, he had found a small blaze among the hot coals. He had doused it for us, but offered a warning that if it was too hot to touch when we put it out, it was too hot to leave.

Our group’s failure to completely extinguish the fire could have been devastating, especially considering California is the country’s most wildfire-prone state. Blazes there have steadily increased over the last few years and eight of the Golden State’s 10 largest have occurred in the last decade. That makes preventing campfire-started wildfires more important than ever.

And while the Forest Service reports that 87 percent of wildfires are caused by people (outdoor equipment, power lines, exhaust sparks, discarded cigarette butts, even arson have been to blame), runaway campfires don’t represent a majority of wildfire ignitions.

However, there have been more improperly built and abandoned campfires this year, says Stanton Florea, a Forest Service spokesperson who focuses on fires. That’s at least partially attributable to a dramatic increase in recreational use of public lands and the relative inexperience of many visitors, he says.

So what’s the proper way to build (and extinguish) a campfire so you don’t accidentally start a wildfire? Build with caution, choose the right materials, and make sure to put it out completely.

Make sure campfires are allowed

While a campfire may seem like an essential part of every overnight outing in the great outdoors, you must know ahead of time whether the area you’ll be camping in allows fires. Some parks and forests only allow them in designated fire rings. Others will let you dig your own. And some ban campfires completely, often in at-risk or fire-prone areas. Occasionally this will be a permanent rule, but sometimes it’s only a seasonal burn ban during times of drought.

Never build a campfire where they are prohibited, but if you are allowed to start a warming blaze, take stock of your surroundings first. If the area is especially dry, it may not be wise to start a fire, no matter what the rules are. The same goes for wind, which can transport hot embers farther than you think—up to a mile in windy conditions.

Build a campfire safely

If conditions are favorable and fires are allowed, always build yours in a designated fire ring or pit if one is available. If not, choose a flat spot of ground at least 15 feet away from tents, trees, and other plant life or camping gear, the Forest Service says. Make sure you look up to check for low-hanging branches, and if there are sticks, pine needles, or other flammable debris around the area, rake them all away so there is a 5-foot area of bare earth on all sides of the fire.

You can also use a fire pan or fire safe: metal bowls or box-like structures that offer a space to build a fire that helps contain the flames while protecting the ground beneath from being scorched. These are helpful in environments where fire could damage delicate plant life or char the ground or rock under the fire.

Then make sure to build your campfire with care. Start by having a source of water nearby such as a bucket or several full water bottles, plus a small shovel for extinguishing—if something goes wrong, you won’t want to waste time finding a way to put it out.

Find your firewood

There are multiple ways to find firewood when you’re camping, but they vary depending on where you are staying. In a developed campground, you can likely buy firewood and fire starters from the camp store or nearby grocery store. Just don’t transport firewood far beyond your campground. Restrictions vary from state to state regarding how far is too far, but you should try to purchase wood as close to your destination as possible to prevent the spread of invasive species like the emerald ash borer.

If you must collect firewood, never cut down live trees or branches. Nor should you pull up dead standing trees or bushes as they may be home to wildlife and native insects. Only collect dead, downed wood that is no larger than your wrist, and only if there are no posted restrictions on collecting it—check signs at campsites, near trailheads, or on park websites.

Ensure the wood is no longer green, as wood that hasn’t had time to dry out will smoke and burn inefficiently. You can tell if wood is green by bending it. If it bends without breaking, it’s likely too wet and green, but if it easily snaps in two, it’s dead, dry, and ready to burn.

Be careful about over-harvesting, though. “When an area has been ‘mined’ of all its dead and downed wood, you can have a significant effect on the ecosystem,” warns Ben Lawhon, director of education and research at the Leave No Trace Center for Outdoor Ethics. The breakdown and decomposition of dead vegetation is important to the health of the land.

To prevent that from happening, walk a few minutes away from your campsite and collect wood from a larger surrounding area. Leave large fallen logs and limbs where they are and collect smaller branches instead.

Maintain your fire

Once you have a fire going, add branches or logs slowly and never leave your fire unattended. Don’t burn trash or non-wood objects as they often won’t burn at all (chip bags and batteries), can spark wildfires themselves by catching quickly and drifting away from the fire (paper plates and napkins), or can create toxic fumes.

In fact, commonly burned items like cigarette butts, candy wrappers, batteries, and plasticware send dangerous toxins such as cadmium, lead, and mercury into the atmosphere, according to a study by the Missoula Technology and Development Center and the Forest Service. Many of the toxins they found are proven carcinogens and are dangerous if ingested or inhaled by people or animals.

Put out the flames

When it’s time to extinguish your fire, do so completely. Let the fire burn out and turn to ash. Then pour plenty of water on the embers and coals, drowning them entirely. The Forest Service advises doing so until all hissing noises stop. Often, that won’t be until the ash is soaked and soupy.

If you don’t have quite enough water at your disposal, use a shovel to stir the damp embers with surrounding dirt, ash, and sand. Continue stirring and raking until no embers are visible, but also until the ash is no longer hot to the touch.

As Smokey Bear says, “If it’s too hot to touch, it’s too hot to leave.” So place your hand directly over (but not touching) the ashes to check the temperature. Do this before you go to bed and again before you leave your campsite.

Leave no trace

Also before you move on, make sure you don’t leave anything behind. If you’re in a developed campground with a fire ring, you may be allowed to leave ash in the ring and leftover firewood nearby (check campground rules first). But if you’re in the backcountry or somewhere else without a fire ring, make sure to follow Leave No Trace Principles before leaving camp.

Scatter unused wood, bring any campfire litter with you, and if you’re in a true wilderness area, collect the wet ash and scatter it over a large area away from your campsite. In undeveloped, backcountry areas, it’s important to make the area appear as if you were never there at all.

Only you can prevent wildfires

“A campfire is as much a part of camping as the tent, but there’s a way to do it without creating unnecessary and avoidable impacts,” Lawhon says. “It just takes a little more work.”

Smokey Bear said it best: “Only you can prevent wildfires.” So remember the lessons from the bear in the ranger hat the next time you enjoy a campfire: follow local rules and regulations, pick a safe spot, build your fire carefully, extinguish it completely, and leave no trace. And don’t forget the s’mores.

Alisha McDarris

Alisha McDarrisis a freelance writer for PopSci and specializes in all things outdoorsy and sustainable. She’s also written for Backpacker, Outside, BBC Travel, and more, plus she's the co-founder, head honcho, writer, photographer, and on-screen personality of sustainable travel and adventure blog Terradrift. When she’s not writing, you’ll find her backpacking, kayaking, hiking, or rock climbing, all while attempting to determine how many times she can wear a hiking shirt before her husband begs her to wash it.