This park has great hiking, which is honestly the only positive thing I have to say about arrowhead. There are several miles of dirt bike trail that is hiker friendly, of various difficulties.
The camp ground itself is well maintained, but tent campers are not allowed to rent ANY of the sites along the lake front. We were the only people at the campground when we were there, and still were not allowed to camp in one of the lakefront spots. The "tent sites" are paved and at very extreme angles, with very sparse to no tree cover what so ever. The sites were essentially on top of each other.
We wound up renting a back up (20' I believe) site for our meager 4 person dome tent. There was water and electricity available, with clean facilities nearby. There is no wind break due to the sparse tree coverage, so pack for a chilly night if the temps dip at all.