Just outside of Bridgeport California. Used to go there every year back in the 70's and 80's, Don't know if it as peaceful and tranquil now. I believe that they now allow both jetski's and water skiing on upper twin, UGH.
I still own my LE SeaDoo PWC, but I just moved to NV and sadly with all the water CA got last winter (and soaked my camper at the time) the Lake Mead is very low. Still lot of water, but I don't like to play with mud. I will save the link for my "older years" as I just semi-retired.