Bill & Shari,
Santee Lakes is a nice park. We go there quite often as its only 45 minutes or so from the house. A really neat park in San Diego County is Dos Picos in Ramona. That too, is less than an hour's drive and it is really neat---great walking paths either through the hills or down by "the pond" which looks like an old WPA project with all of the rockwork for the spillway. Check out this site: http://www.co.san-diego.ca.us/parks/
Go to the on-line reservation system and it shows you an actual view of each site & its availability. But back to your original posting---it is quiet and the rangers are very receptive to helping keep it that way...! Have fun.