A lot of thought was put into the idea of whether to use a water tower with a "P" painted on it, or to construct a giant "P".

It was purposely placed in a spot that could be viewed from three specific locations: the administration building's porch, the newly constructed Highway 101, and the air, as flying was becoming popular.

A 1919 issue of the Cal Poly San Luis Obispo student newspaper, The Polygram, states that one morning Poly students awoke to discover large “H’s” (for High) constructed out of stones on the hills surrounding San Luis Obispo.

Poly students began to concentrate their defense on a hillside overlooking the campus, where the “P” has graced the hill ever since.

Under the supervision of the sophomores, the freshmen dorm boys maintained the 24-by-40-foot (7 by 12 m) “P”, tidying up its stone outline and refilling it when needed.

The concrete “P” was also built by the Block “P” club and was overseen by then student body president, Harry Wineroth.

The social fraternity, Delta Sigma Phi and a group of agricultural engineering students stepped in to help build a long-lasting “P”.

Cal Poly San Luis Obispo's biggest rivalry was Fresno State.

Each year, on the night before the big football game, Fresno State students would climb up to the “P” and change it to an “F”.

One Friday night hours after the lights were out … there were rumors … that the school we were playing on Saturday was going to deface the P. While trying to wake another friend, I was met by Captain Deuel [the dorm monitor].

Clubs are permitted to paint the "P" provided they obtain permission from the Mustang Maniacs and repaint it to its standard white within a reasonable time.

The "P" has started sliding down the slope of the hill and is suffering from some stress fractures due to the movement.

In a response to the Sept. 11 terrorist attacks, the campus painted the concrete letter with the stars and stripes of the American flag.

Immediately, a group of 15 to 20 students were caught with “John Deere green” paint trying to cover up the rainbow.

They want to shut us up.” -Mike Sullivan, a computer engineering major and former president of Gays, Lesbians and Bisexuals United [7] As the controversy around the rainbow grew, minority students and professors held a march to protest Cal Poly San Luis Obispo's lack of diversity and tolerance.