If Yellowstone is booked solid, you will likely find that every campground within a very wide radius of the park is full too. This Trailhead camping is free and open. Remember, this is bear territory, follow all bear safety guidelines. The road leading to the area is pretty well maintained.
I accidentally found myself in Yellowstone on what must have been the busiest weekend of the year. Two hours of stop and go traffic to get into the park, and no camping available that day. I resolved myself to waking up at the time the reservation office opened the next morning to try to get any cancelled reservable spot that opened up, but no luck. A nice ranger told us that Indian Creek is almost always the last campground to fill up, so we booked it over to the campground to try to get a spot. Note that Indian creek has non reservable spots, as do many campgrounds in yellowstone, which means you need to get there in the morning and get your spot before they fill up. We rolled into indian creek around 7 am and got one of the last 2 spots available in Yellowstone.
This campground is quiet, has bear boxes for your food, and has a few vault toilets available. Each site has a picnic table. Not much in the way of shade or natural barriers from your neighbors, but when you need a cheap place to stay and you don't want to drive hours to get out of the park, this place is great.
Get a permit to stay in the campground, or practice leave no trace dispersed camping in the forest, following state guidelines. Two inlets is a beautiful place with dark skies, a great choice for sky watching / meteor shower nights. The primary forest road is fairly well maintained and passable with standard vehicles.
The cheapest place to camp on the west side of Maui. Located on the southern shore, the camping is all beach camping right along the beautiful coast. Trees for shade, porta potties for bathrooms.
Permits must be acquired at one of two government offices. Note that there is a sizable population of transient travelers who seem to live at the beach full time, and no maintenance seems to be done aside from the occasional trash and bathroom cleaning. Bring your own Toilet Paper as it seems to go fast. You are located between the beach and the highway, so it will be noisy but a steady calming sort of noisy.
Easy beach living, the low maintenance traveler will find themselves right at home here.
One of the few completely legal free places to stay on Maui. Why is it free? This campground is in the cloud layer, so be prepared for a humid moist stay. You would be hard pressed to get a fire going here. This campground is past 7,000 ft so be prepared for high winds and cold temperatures. If you enjoy cold weather you will get a great night of sleep here.
This campground is permanently closed
This campground has nearby bathrooms and outdoor showers. It is located with a beautiful view of the black rock beach and the nearby blowhole. Lots of grassy areas for tents. A very family friendly location.
Remember, if you book online, which you should, you need to print out your permit and display your permit on your tent. Rangers come around daily.
If you are the type of person who likes to shower and have clean bathrooms nearby this is your only camping option on the eastern side of maui. (Other nearby camping options have porta potties and you can always drive a few blocks to a beach park with bathrooms and showers.) Unfortunately camp olowalu is overrun by roosters, so you aren't going to get a good night of sleep. The shaded trees are beautiful but they block out any of the lovely ocean breeze that usually makes night temperatures tolerable. There is supposedly reef for snorkeling at this campground, but it seems as though the reef in this area has been completely destroyed by human activity. Overall, one of the most expensive camping options on the island, and the vibe there didn't suit my style.