If you don't want to be IN Fresno, but within an hour, you could try Codorniz Recreation Area (COE). They have some sites with full hookups, some with just water and electrical, and some dry. They also have a dump station on the way out. It will be hot, but lots of wildlife. It's on Eastman Lake so you could do some fishing when you're off. It's in Raymond. About 30 minutes east of Chowchilla and Hwy 99.