Out of Mylor heading to Echunga, only about the second intersection on the RH side, called Silver Lake Road.
The lake is probably a k or so down on the RH side, from memory some big trees around it, sort of neara house, doesn't look very big, was really deep though.
Can't really remember where the track was though, I seem to recall that it was further to the right from where the lake is, but I may be dreaming, it was a long time ago.
Just looked up on google earth, Silver Lake Road, Mylor, South Australia
Shows the lake, bigger than I remember, but I can't see any signs of a track