In the 1920’s there were several students on campus who were quite the jokesters, leaving “A”s on different buildings and structures on campus. In the early hours of March 31, 1920, Aggie students trekked up the mountain and arranged a large “A”, 330 feet tall or roughly the size of a football field, on Tortugas Mountain. The next day, April 1, students gathered at the base of the the newly formed “A” Mountain and began creating a line of students from the bottom to the top of the mountain, passing along old milk cans full of whitewash to paint the A. The tradition soon developed to repaint the “A” each year on April 1st, known as "A" Day. It is one of the strongest traditions at NMSU, and many of our alumni cherish this memory.
Now the “A” is painted during Greek Week as the Greek Community’s Day of Service. Tortugas Mountain is also home to one of many NMSU's Astronomy Observatories. The “A” is frequently lit up for various events and activities such as Aggie Welcome Week, Tough Enough to Wear Pink Week (our local breast cancer awareness campaign), and home sports games. This is one of the biggest Aggie landmarks and lets anyone who visits or returns to Las Cruces know that this is home to the NMSU Aggies.