This is from the San Jose Mercury News of Feb 27, 2006. Perhaps others know of similar camps.
Camp Winnarainbow
What : Learn circus and performing arts skills – juggling, tightrope walking, trapeze, unicycle, dance of all forms, theater, gymnastics and art.
Where : Black Oak Ranch near Laytonville in Mendocino County; winter headquarters in Berkeley
When : June 19-Aug. 19
Contact : (510) 525-4304, www.campwinnarainbow.org
Ages : 7 to 14; there is also an adults only camp in early June
Details : $1,450 for two-week session, $720 for one-week session; campers sleep in tepees; the camp is on a lake and has a 350-foot water slide