I've thought long and hard about this topic, and I believe that openly allowing firearms in the national parks will open the proverbial box to a lot more grief than we want. I said "openly" because you have a very quiet option of taking the weapon along and using it for the sole purpose of defending your life or others. At that point, you will find out if a prosecutor truly wants to mby Dearborn - General Discussion
It sounds like you may have found the Anderson Trail, constructed by George Anderson, the first man to scale Half Dome. "Anderson's trail from Happy Isles to Vernal Fall was constructed at great loss to its builder in 1882." - 100 Years in Yosemite, Carl P. Russell, p. 109.by Dearborn - Backpacking and Hiking Yosemite and the Sierra