I think it is, but it's dusty with lots of traffic and a very narrow canyon. Half the year the stream doesn't run and there is no water. Don't know why anyone would camp there. We wouldn't go back. Did nothing but clean dust out of our camping gear (not to mention our sinuses) for days after we returned.

Not an official answer - check with the ranger station, BUT... I've seen people stay there all year round. Just don't be a problem.