Campfires are one of the best and most popular camping traditions. Most places you will camp may already have a fire pit. Developed campgrounds almost always one and many times you will find left over fire pits in dispersed camping areas built by previous users. It is almost always advantageous to use a previously used site when doing dispersed camping and is more friendly to the environment. Having a ready-built fire pit in a previously used site saves a lot of time and effort and often you may see where other vehicles have already been parked on the most level part of the site. Many campers bring their own portable fire pit with them for use where ever they go.
The rock ring fire pit is one of the most common forms of fire pit. Easily constructed from loose rocks they are not only popular in dispersed camping but you will often find them in developed campgrounds. If you need to build your own the process is a little tedious but well worth the effort. Begin by clearing the ground where you will build your fire all the way down to the dirt. Remove all flammable material such as twigs, branches, weeds, and roots. Collect enough rocks to make a circle the size of the fire you want to build. A fire pit with a 3' diameter is usually about right for most family or small group campfires. If you are solo camping you might want a smaller one or, if you will have a large group around the campfire, make it bigger. Usually something about 5-6' across is adequate for most groups. Beyond that you're moving into the area of bonfires instead of campfires! You can use just about any size rocks that you can move by yourself. I find that those 8" to 12" are about the right size for most fire pits. If you use smaller rocks you may have to pile them up to form a little rock wall about 8" to 12" high. Then scoop out the dirt from the middle of the fire pit to build a little embankment against the inside of the rocks to block drafts. Before you light your fire be sure to clear the ground outside the rock ring of all flammable material for at least 5 all around. Stack your fire wood outside the cleared area. The cleared area helps prevent an accidental spreading of your fire and gives you a good place to sit to enjoy your fire.
If there are no rocks around, dig down a little bit and build a berm to make a fire pit.
You need something to define the fire area and contain and control the
spread of hot ashes once the fire gets going. A rock ring or berm also
helps mitigate ground-level breezes that might have an adverse affect
on your fire like making it hard to light or blowing embers that might ignite surrounding materials.
Metal fire rings are found in some developed campgrounds. Sometimes they are as simple and mundane as a section cut from a 55 gallon steel drum. Other, more decorative ones are formed from sturdy sheet metal and often have woodland or wildlife scenes cut into them so you can watch the flames dance behind the cutouts. Watching the campfire is always enjoyable and the cutouts make it even more so. You can purchase metal fire rings to bring along when boondocking, if you have room to carry them. Some are even collapsible for easy storage and transport.
My favorite portable fire pit is an old washing machine tub. We call it R2D2 (because of its squat round shape and the way the fire sparkles through the perforations like R2D2's lights) and have used them for decades after being introduced to one by a fellow dirt biker. With their porcelain finish they are both easy to clean and very durable. In fact, we've been using the same one in my dirt bike trailer for more than 40 years! Most washing machine tubs have center tube where the agitator used to be. Sometimes that gets in the way of putting wood in the fire but if you cut your wood the right size that isn't a problem. I make use of the center tube by sliding it down onto a cut-off RV table post and using a 3-pronged portable table base. I cut the table post so the top of the tub is a comfortable height for cooking. It also makes a nice space beneath the tub to warm toes on cold nights. I bolted a pipe flange to a wire grill from an old BBQ to install the grill on the fire pit using the top of the agitator tube. The perforations in the tub protect the fire from wind gusts yet allow sufficient circulation for a good burning fire. At the end of the night I put a trash can lid on top. When its time to pack up it is easy to dump out the ashes. The holes in the washing machine tub flicker enchantingly when with the flames. It is a bit large to haul around in the family car but it fits well along with our dirt bikes in our motorcycle trailer. We like our R2D2 so well we put one in the fire pit in our picnic area by our house and anchored a second one in a little cove for a fire pit down by the McKenzie River behind our house.
If transportation space is an issue you can find collapsible fire pits. They are often made of metal panels, sometimes wire and sometimes solid sheet metal and can be folded flat so they take up little space in your car trunk or RV cabinet.
Gas fire pits are becoming more popular, especially with RVers. They are clean, easy to transport, set up and light, and you only need a small propane cylinder to run them, They may lack the fragrance of a wood fire but still provide the same warmth and ambiance. To put out the fire simply turn off the propane supply. You can buy wood chips to sprinkle on some gas fire pits to add fragrance to the smoke and flavor to anything you cook over it. You can run them off the propane tank on your RV using an Extend-A-Flow kit that taps into your RV propane system near the tank. Sometimes you may still be able to use a gas fire pit during early stages of fire restrictions where real campfires are prohibited.
As mentioned in the first paragraph, clear the ground of flammable material for 5' all around ANY campfire as a safety measure to make sure your campfire doesn't spread. You should still clear the area around gas fire pits to prevent burning material dropped from items cooked over the campfire from igniting fire outside the fire pit. Marshmallows seem to have a wondrous way of flaming up even when you are going for golden brown!
It can be fun in these pits!