Yes I have used my own lifelong experience as well as my friends, relatives, Boy Scout troops, forest rangers etc. They are physical landmarks for hikers, hunters, Boy Scouts, forest service rangers etc. that have been used for many decades.  I have witnessed in person countless times what is questioned that is uploaded to the map and so have countless others. Many take photos of the gooseneck tree with their families or otherwise when hiking or motorcycling to gunsight peak up winter canyon. It's all legitimate on ground reality.