A valuable group of resources within Yosemite National Park’s backcountry are the blazes left by individuals who used the backcountry in a variety of ways. Styles range from the vertical lens of sheepherders Q to the uppercase T of the military to the more recent U.S. Forest Service I . “Some wags stoutly maintained that the ‘T’ was used as [the] symbol so that the Irishmen in the army would know that it was a tree!” Although the early sheepherder blazes marked trails and grazing areas, some figures and designs appear to be simply efforts to pass the time. The army used the T mark between 1890 and 1914, possibly ending as early as 1906, to aid backcountry patrols, especially after snowfalls. After that time Gabriel Sovulewski, in charge of trail work, used a diamond-shaped blaze, which was used into the 1930s until he retired.