Here is another of the authors early encounters with a scary bridge. This snow bridge was located on the Wonderland Trail where it descends from Ipsut pass into Carbon Canyon. It was created as a creek carved a tunnel through a snow bank. As the snow bank melted and the tunnel grew a natural arch formed - located right where the Wonderland trail crosses an upper fork of Ipsut creek. Thus forming a bridge which provides a very unsafe way to cross the creek without getting your feet wet.
Making the situation even worse, the situation was only clear from below. When descending it appeared that the trail simply crossed an ordinary snow bank. The first time the author crossed he was carrying a 40lb backpack and did not recognize the danger. Upon decending the switch back below the situation became clear; the rest of the group was advised to avoid the crossing. It was concluded that a 2nd crossing could be made without the backpack, allowing this photo to be taken.
The bridge undoubtedly melted over the following weeks. It is not known (to the author) if the bridge collapseda hiker crossed it, but it clearly posed a significant hazard.
In 2014 the author returned to the area only to find that everything except the trail is densely overgrown. It was not clear if this bridge reforms every spring, or if it was a chance occurrence. Maybe someone will fund a research grant to investigate this issue?
There are far more dangerous snow bridges nearby on Mt. Rainier. However, it is hard to find one placed so neatly on such a well maintained trail.