There's a neat one at the Hunnewill guest ranch in Bridgeport CA on Halloween weekend that Cindy goes to each year. It's reasonably priced and a lot of fun.
They may still have openings for this year.
Cindy's blog post from last year:
http://www.quilt-kits-online.com/notebook/?p=878
Contact info for the Hunnewill ranch:
http://www.hunewillranch.com/
They will know who to contact to see if there are openings.