Hillside letters or mountain monograms are a form of geoglyph (more specifically hill figures) common in the American West, consisting of large single letters, abbreviations, or messages emblazoned on hillsides, typically created and maintained by schools or towns. There are approximately 500 of these geoglyphs, ranging in size from a few feet to hundreds of feet tall. They form an important part of the western cultural landscape, where they function as symbols of school pride and civic identity, similar to water towers and town slogans on highway "welcome to" signs in other regions.
A long-standing myth that hillside letters were built to identify communities from the air for early pilots who air-dropped mail is untrue. The first three mountain monograms built were constructed to end rivalries between different graduating classes at universities. Letters have also been erected to celebrate winning teams, to commemorate the building of high schools, in memory of local community members, and as Boy Scout projects.
The first hillside letter built is the "L" in 1904 representing Lahainaluna High School. This 30 foot letter "L" at about the 2000 ft level on Mt Ball, part of the West Maui Mountains was created by students of Lahainaluna High School [established in 1831] by clearing the plants and weeds and adding lime to prevent regrowth. It is still lit up annually during graduation ceremonies.
The second hillside letter built was a C in March 1905. It was constructed out of concrete and placed on Charter Hill overlooking the UC Berkeley. The UC Berkeley classes of 1907 and 1908 proposed this project as a means of ending the rivalry and the unruly physical encounters that had become a part of their annual rush each spring. The UC Berkeley yearbook would later record that the two classes would go down in the history of the University as those who sacrificed their class spirit for love of their alma mater.
In 1906, Brigham Young University in Provo, Utah, proposed and surveyed the first three-lettered hillside emblem BYU, but reduced it to the single letter Y after realizing the amount of labor involved. The following year, the class rivalry of the sophomores and freshmen at the University of Utah in Salt Lake City produced a hillside U on Mount Van Cott overlooking Salt Lake City.The M for the Miners of the Colorado School of Mines in Golden, Colorado, became the nation’s fourth hillside letter in 1908, and it has been illuminated every night since the early 1930s. A few years later, high schools began building hillside letters; the first one was a T for Tintic High School in Eureka, Utah, built in 1912.