There's room for a trailer, and the rest area is open 24/7 but definitely don't camp there. If you get into the valley late and don't want to go blundering about trying to find a site somewhere else, it's probably fine for a nap, though. That said, there are several USFS campgrounds in the same area for $7 a night, most of which have decent trailer sites. Mallard's Rest has the biggest sites, but Eagle Creek is pretty good, too. Canyon is tight and the few big sites are usually occupied.
Not at the moment I believe most things are closed still till end of month or may. There was still bunch of snow last week
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