Fritz Weissner was a German-born immigrant that came to America in 1928.  While in Europe, Fritz had had experience climbing Himalayan mountains and boasted much climbing expertise.  Fritz had a quite unusual body architecture.  His frame was frequently described as "stocky" and boasted a 5' 6'' height, a noticably shorter height that was seen as quite disadvantageous to the sport.  When he came to America, Fritz brought over a mastery in a technically difficult type of rock climbing: wide crack climbing.  

He began establishing and performing first ascents on many new climbs throughout many locations, but most noticably Wallface in the Adirondacks.  Wallface is particularly noticeable for being the tallest cliff on the region and perhaps Fritz's most famous Adirondack route.  Four routes in particular bear the name, "Wiessner Routes."  These are spread out over the adventurous landscape, in Wallface, Noonmark Mountain, Indian Head, and Mount Colden.  These routes are known as classics with a certain amount of timelessness to them.  Phil Brown, avid rock climber and Adirondack writer, notes that when climbing these, he feels, "In the footsteps of giants."  due to the sheer amount of history on each one of his routes (Brown, 1). In total, he created and lead eighteen routes in the entire region.  His other locations include Connecticut, New Hampshire, South Dakota, and Wyoming. 

Fritz made climbing his life, and the Adirondacks were a perfect venue in order to enact this.  When discussing Frtiz's life dedication to climbing in an interview with climber Steve Grossman, Grossman explains the most profilic statement he heard from Fritz on their Mt. Lemmon ascent.  Fritz said, "When I cannot climb, I want to die" (Rupley).  He helped bring popularity to the sport and is known as one of the most famous climbers in American history.  Fritz continued climbing well into his 80s, where he died in 1986.