There is a far greater risk of being mauled by a bear in the Bird  Creek area than being hit by a meteorite. Bird creek has a large population of black and brown bears. And right before the salmon get into the area these bears are hungry, cranky, and totally unpredictable. It is just a matter of time when there is interaction between them and humans. I happen to believe that these interactions constitute a reasonably foreseeable risk to anyone on the trails. Meteorites might hit a human one in a billion. Bear interactions, maybe one in  a thousand or five thousand. That is an unreasonably high risk that needs to be addressed in some way not the least of which is to inform participants.