"The debate over who should use the roads and paths of the country's national parks is consistently fraught. In California's Sequoia National Park, unkind words are sometimes exchanged when pack animals with their wide panniers encounter hikers kitted out with the latest R.E.I. gear on the trails behind Mount Whitney. The code of etiquette and safety governing such encounters is sometimes ignored, And there have been continual efforts to ban horses, burros and llamas because of their impact on the trails."
"This year Congress intervened to permit stock packing on national parklands in the Sierra after a court ruled in a lawsuit filed by the High Sierra Hikers that the current system for permitting stock violated the Wilderness Act.
Now bicycles are becoming part of the whose-trail-is-it debate. On Friday, the National Park Service published a final regulation in the Federal Register giving individual park superintendents the power to allow bicycles on existing or new roads and pathways."