Why is there a giant ‘P’ on SLO hill? An ‘M’? Learn stories behind iconic initials
From a bird’s eye view, the terrain of of San Luis Obispo County is anything but flat.
The area’s many mountains and hills jut out from the landscape while agriculture and homes fill in the various valleys.
The county is home to the Nine Sisters, a chain of volcanic plugs stretching from Islay Peak near San Luis Obispo County Regional Airport to Morro Rock in Morro Bay.
Generations of residents have left their trace on the local landscape in the form of massive letters.
People connected to Camp San Luis Obispo, Cal Poly and local schools ranging from Templeton High School to Mission Prep in San Luis Obispo have made their marks on well-known vistas in the area.
Here are the origin stories behind some of the hillside landmarks.
Where did the Cal Poly ‘P’ come from?
The Cal Poly “P” is a giant concrete letter measuring 35 feet wide by 50 feet tall. It stands on a northwestern hill overlooking Cal Poly’s campus.
Heralded by the university as “one of the oldest hillside initials in the West,” the history of the massive initial dates back more than 100 years.
That’s when a heated rivalry arose between students at Cal Poly and San Luis Obispo High School.
According to a 1919 issue of Cal Poly student newspaper The Polygram, now known as Mustang News, a feud broke out after high school students moved several large stones into an “H” shape — standing for “high” — on hills around San Luis Obispo.
Cal Poly students responded by reorganizing the rocks into a “P,” for “Poly.”
The youngsters battled back and forth, with Cal Poly students eventually focusing their efforts on creating a “P” on a hillside overlooking the university’s campus, according to Cal Poly’s Robert E. Kennedy Library.
It’s remained at the site ever since, according to the library.
“Born out of rivalry, the P now shone as the symbol of students’ pride in their campus,” Cal Poly said on its website.
Over the decades, freshman students trekked up the hill to freshen up the massive letter ahead of fall homecoming games. Students used layers of lime to redraw the stone outline and camped out overnight to protect the Poly P from rivals, according to university archives.
Eventually, the letter’s stone structure was replaced by a larger concrete configuration on May 3, 1957.
Cal Poly fraternity Delta Sigma Phi led efforts for the letter’s revamp, getting local businesses to donate supplies and calling on agricultural engineering students to drive tractors and materials up the foothill, Cal Poly said.
Throughout the Poly P’s 106-year-old history, the letter has become a “long-standing campus tradition, often reflecting the temper of the times,” the university said.
The Poly P was used to spell out “GOP” in 1964, “POT” in the 1970s and “SPRINGSTEEN” in the 1980s.
Students have twisted white bed sheets to form different letters, including the titles of campus clubs, fraternities and sororities, and incorporated the P into a plethora of marriage proposals over the years, according to Cal Poly.
Is there another giant ‘P’ on SLO hill?
A second, less famous Poly P rests on another local hillside.
The P can be found on the open face of Bishop Peak, a 1,546-foot volcanic plug in San Luis Obispo that’s one of the Nine Sisters.
Cal Poly student Walter Lumley painted the big initial 99 years ago.
In a letter found in Cal Poly’s archives, Lumley described his four-year obsession to paint the landmark with a P to represent his university.
In 1926, he convinced an agriculture department teacher to lend him a long rope, paint, brush and a small bucket. He and three friends drove as far as their truck could take them uphill, then trekked on foot.
Lumley tied a rope around his waist and then began slowly clambering down the rock face.
Over two days, he used 10 gallons of lead paint and a 4-inch brush to make the 40-foot-tall, 24-foot-wide letter.
At times, Lumley wrote in his letter, the project became a tad treacherous with wind and cold weather hammering him on the hillside.”
However, he added, “There was never any choice of turning back.”
In the end, he was happy with his work, calling it a “good looking P.”
According to Lumley’s letter, the second Poly P was given a fresh coat of paint in 1954.
Why is there a massive ‘M’ on SLO’s Madonna Mountain?
For years, rumors have circulated that the massive M perched on top of Cerro San Luis — colloquially called Madonna Mountain — is a nod to the influential Madonna family.
The Madonnas founded San Luis Obispo’s famed Madonna Inn, and own parts of the peak just west of downtown San Luis Obispo.
However, the M originally stood for Mission Central Catholic High School.
The San Luis Obispo private school — now renamed Mission College Preparatory Catholic High School — said on its website that the initial was first constructed in 1964 after senior students built a big wooden letter and then lugged it up the hillside.
During its first year on the mountain, the initial was often rearranged and vandalized, Mission Prep said, causing the 1966 senior class to lead a renovation project.
This was not a simple feat, the school said. Students had to obtain permission from Edison French, the landowner at the time, and figure out a way to move loads of concrete up Cerro San Luis.
Over the course of several weekends, students used a pulley system to get building materials up to the work site, braving copious amounts of poison oak.
At one point, San Luis Obispo High School students ruined all of the concrete sacks their Mission counterparts had stored, Mission Prep’s website said.
The Catholic school students, who called themselves the “Lively Ones,” eventually rebuilt the M using concrete and rebar, creating the more permanent letter seen on the mountainside today, the school said.
“The ‘M’ is a vibrant symbol of class unity for students of Mission Prep,” its website said.
What’s the story behind the Templeton ‘T’?
In the spring of 1955, senior students from Templeton High School gathered leftover construction materials from a public pool project to craft the enormous hillside landmark, the Paso Robles Press reported in 2024.
Since the letter was painted onto the southern-facing hillside, volunteers called “T-Keepers” have collaborated to preserve the community emblem and protect it from pranks, the Press reported.
Over the past 70 years, the hillside letter has been used to symbolize class pride, commemorate tragic incidents in the community and celebrate local high school graduates, the Press reported.
Today, the Templeton High “T” sits on Pat and Leslie Jones’ property.
Leslie Jones, a self-proclaimed “T-Keeper,” told the Paso Robles Press that the landmark has been “a joy” to have on their land.
This story was originally published June 22, 2025 at 5:00 AM.
CORRECTION: A previous version of this article listed an incorrect title of the local high school responsible for the ‘M’ on Cerro San Luis. At the time, the school was named Mission Central Catholic High School. The error has been corrected.
