NOTE: The report from Bob Gross has this box SE of the lake, but that's probably wrong, based on the misleading rotated map provided on the sign by the lake, which shows the east-northeast shore facing southeast if you don't notice the north arrow on the map.
(lat,lon) = (36.6662500, -118.6946900) in decimal degrees, NAD83. (zone,east,north) = (11S, 348628.0, 4058991.0) in decimal meters, NAD27.
Map exported from TOPO! software, used with permission.