There is Camp Watcha Patcher held for 1 week in Costa Mesa, CA. They have a web site. I think it is in July.
There is a wonderful place called Inspirations in Big Bear. You just call and plan when you want your retreat to be.
I think Calico House in Yorba Linda, CA has one. They have a web site.
Also, I think the Orange Quilt Bee in Orange or Buena Park has one and they also have a web site.
There is a site called Quilters Escape. They have a web site too.
I can't check the web addresses right now, but like someone slse said, try searching quilt retreats calif.
Some advertise in national quilting magazines like Quilters newsletter.
Good luck
Verna in So CA