It ain't no "wilderness" but it's not a "sewer" either.
On 8/8 I met a ranger coming down from collecting water samples for coliform. He stated that even Trail Camp Lake is pretty clean, and that even the LA aqueduct itself sometimes tests positive while it sucks the Owens Valley dry.
Trail Camp did smell a bit, though. I collected my water up at the faster flowing inlet, and used chlorine dioxide
