Every attempt was made to provide accurate information for this article, however things do change. An example is that the San Joaquin River Gorge Management Area in Auberry in the past had free camping however they now charge a fee. Therefore please use this as a guide, however call in advance to ensure that there is still free camping in the area.
The first area is more car camping that tent camping. It is a great place to park and boondock. There is a large parking lot and a large dirt patch and you will often see multiple semitrucks here. it is Harris Ranch in Coalinga. They have free water and often you can use the showers for free. The great thing about this is that it is a quick drive to many hiking areas in the mountains. Another great thing about this place is that is close to not one but two large freeways so it is a very easy and quick drive from Fresno.
The second area is the Dinkey Creek Road which is about 40 minutes from Fresno in the Shaver Lake area. They typically have free boondocking in the trees. Boondocking otherwise known as dry camping is common, so there are many times you will not be able to find a place to do so. However, there is a backup plan. There are some paid camping sites that usually have room nearby and are relatively inexpensive. Many less than $20 a night.
Another great option is the Kirch Flat Camp in the Sierra National Forest. This beautiful site is located on a pretty sandy and flat area amongst oak and pine trees. They have boating, fishing, hiking, birdwatching, fire rings, picnic tables, and beautiful beaches here and typically you can camp for free.
If you want to visit the Kings River consider the North Fork Confluence. This area has dispersed camping so you get to enjoy nature with little disturbance from other people. There is great white water rafting, fishing, and camping in the area. Another option on the Kings River that is extremely close to this one is Camp 4 1/2 in the Sequoia National Forest. This is also a large sandy area for camping although the sites are much less dispersed. There is great shade throughout the camping area provided by the oak and pine trees. If you want to go just a couple miles further into the Gravel Flat Campgrounds in the Sierra National Forest you can also enjoy free camping. This is on the north side of the Kings River and just like the other sites it has a sandy flat area and great fishing, boating, rafting, picnic, and bird watching opportunities. The difference from the other two Kings River sites is that this one has almost no shade.