Lifey,

It so happens that some nephews and nieces were in town over the weekend and at their request we went to Biosphere 2 for the tour. So yes, tours are still being conducted, or they have been restarted, now that Biosphere 2 is operating under the aegis of the University of Arizona's College of Science. But the non-discounted tariff is rather steep, around $20, and it is a fairly long tour, on the order of a couple of hours if you do the self-guided bits after the docent-led portion.

AZBuck