The School of Mines "M" on Mount Zion is one of the largest mountain-side monuments in the nation. Resting on a 23' slope at 6,900 feet above sea level, the letter is 104 by 107 feet in size. It was designed in 1905 by Joe O'Byrne as a problem in descriptive geometry. The descriptive geometry problem was extremely difficult because the "M" was to appear undistorted from any angle of view. In 1908, 250 students and 20 faculty members, with a supply train of loaded burros, packed their way up Mount Zion to build the Colorado School of Mines "M". By late that afternoon, the nation's second oldest mountainside monument had been constructed. Only the Utah "U" outdates the Mines' letter. In 1931, members of Mines' chapter of Blue Key, a national leadership and service fraternity, borrowed a tractor, a generator, poles, wire and bulbs to light the "M" for Homecoming. The impressive display prompted students and civic committees to organize a fund drive to raise money to light the "M" permanently. The feat was finally accomplished in 1932. Originating at Brooks field, a 230 volt line carried current over 17 poles to the "M"-blem. The power was transformed to 110 volts and fed to the letter's more than 400 bulbs. In 1935, Blue Key decided to change the color of the "M" for the Christmas holidays. Each year since, the large letter has been changed to red or green. Lighting became fully automatic in 1948. In the fall of 1989, after 41 years with only minimal maintenance on the "M"-blem lights, Blue Key spearheaded an "M" modernization project. In the initial phase of the project, the old lighting structure was removed and a new support structure was installed by Blue Key and members of the Society of Mining Engineers. The "M" was then rewired and all wiring was enclosed in a weather-proof conduit. The old light sockets were replaced with multi-bulb weatherproof fixtures. This project provided the capability to control the lighting via a phone modem. Due to the extremely poor condition of the power lines, high winds cut power to the "M" in the Fall of 1989. Using funds provided by the class of 1952, the power lines, transformers and several poles were replaced and the system upgraded to 760 volts. During the repairs, the "M" was lit using a portable generator with Blue Key members manning the generator throughout the night. Each fall, freshmen carry ten pound rocks to the "M", clean it, and paint it white. Again in the spring, graduating seniors whitewash the "M" as a parting gesture. Today, the "M" remains the largest single illuminated letter in the country. It is very susceptible to raids by students from other schools, electrical storms, and high winds, but the "M" has never been out for very long. The "M" stands for Miners, the School, and above all for Mines Spirit.