Heidi,

  Oso Corridor is a segment of forest trail on the east side of the Sandias down from the Ski area.  It basically starts at Doc Long camp area and goes uphill (up and down and around) until it joins the Tree Spring trail further up the mountain.  It is a wonderful trail that lends itself to motoring along in a beautiful setting, albeit at some points quite a workout on the climbing direction.  This is the sort of trail that a booby-trap would work well on since most folks are either head-down on the climbing, or moving quickly enough on the downhill that this sort of thing is very easily missed.  This kind of sabotage of the trail system (if it was deliberate, and it sounds like it isn't entirely provable that it was) is extraordinarily dangerous since there is no time to prepare for the impact or even to dodge it.  Over the years I have seen quite a few things that were obviously put in place to hamper, hinder, hurt, or harm the mountain bikers that are using our forest trails legally.  I don't want to classify those who would do such a dangerous and reckless thing, but I seriously doubt it was someone out there on a bicycle.  Just sayin'.