I took one of the last tram tours ever, through the Mariposa Grove of Giant Sequoias in Yosemite National Park last month.  In an effort to preserve and restore the grove, the tram has permanently stopped running.  In the Spring of 2015, there are plans to remove the roads and have the grove to go back to nature.  Hopefully the trees will continue to flourish without the weight of the tram causing stress on the roots of the trees.  The restoration of the Mariposa Grove is expected to be completed in November 2016.