Here's a little blurb with some history: http://www.prnewsnow.com/PR%20News%20Releases/Lifestyle/Cask%20Cleaver%20Restaurant%20to%20HoldFundraiser%20for%20YMCA
It says that the camp was a gift from the Lackeys of Corona, CA, to the Riverside YMCA in 1949 and that maintenance and access problems forced the sale of the camp in 1990. I guess a toilet in your swimming pool will do that to you.

It says nothing about the BSA or fatalities, but I suppose that could have happened post 1990.