There appears to be some confusion over "Lost Lake campgrounds", there are more than one in Oregon.
One in Mt Hood and this one on the Santiam Pass area.
This one is a few spacious ,nice campsites spaced out around seasonal lake.
The lake dissapears down some lava tubes under the surface, so by high summer there is just a swamp with some pools.
Nice place to see wild life,
There is a couple of vault toilets buts its a long walk from most campsites during the night.
very peaceful even if its just off the main highway.