To the west you can see a basaltic peak adorned with the letter "A." This was once a lookout for Spanish and Native American sentinels, who watched for raiders approaching the mission that was once located at the base of the mountain, as well as the Presidio San Agustín del Tucson, located across the Santa Cruz River in what is now downtown Tucson. The Tohono O'Odham called their settlement at the base of the mountain "Chuk Son," which means "at the black base." This is the source of the name Tucson. The “A” was added in 1915 in a burst of University of Arizona student enthusiasm, as the result of a football victory over Pomona College. A member of the team and a civil engineering student suggested to their professor that the class should survey the mountain for a good location for an “A” for Arizona. Students worked weekends to clear the site, dig the outline of the letter and haul the mortar/water mixture up the mountain. The “A” is 70 feet wide and 160 feet tall. A plaque providing more information about Sentinel Peak/"A" Mountain is located close to the Jacome Art Panel.