Written by Taylor Mogavero, Program Coordinator

If you’ve ever walked Devil’s Slide Trail in Pacifica (the old US-1 road before the Tom Lantos tunnels were built), you may have noticed a sign dedicated to a very important local. Her name was Ollie Graham Hendricks Mayer. 

Ollie Graham Hendricks Mayer

Ollie Mayer was one of the San Francisco Peninsula’s most successful and effective environmentalists to date. She championed efforts to protect and preserve the San Mateo County coast from the 1950s until her death in 2013. The very reason the Devil’s Slide Trail was converted to a walking trail was due to her long years of activism. Ollie was the president of the Loma Prieta Chapter of the Sierra Club and spent her time ensuring the protection of redwood groves and the creation of hiking trails we enjoy today. After traveling the world for a year, she was inspired by the hiker’s huts she saw in Europe and wanted the same in the Santa Cruz mountains. In 1977, she built the Ollie Mayer Hikers’ Hut in Sam McDonald Park which can still be visited today. 

Devil’s Slide Trail in Pacifica

Olive (Ollie) Graham Hendricks was born in 1918 in Maplewood, New Jersey. At 16 years old, Ollie attended Swarthmore College where she majored in engineering. Upon graduation, she was the only woman engineer in her class and only the second woman to graduate with an engineering degree from Swarthmore. After graduating in 1939, she went to the University of Michigan where she obtained a master’s degree in engineering. 

Ollie Mayer Hiker’s Hut

During her college years, she discovered her love of the outdoors and hiking. She would often go on solo hiking trips alone. In 1941 on a solo trip in the Rocky Mountains in Colorado, she met a young doctor from New York City who would become her husband, Henry Mayer. Both of them loved hiking and went on many hiking trips together, including climbing the Grand Tetons in Wyoming and becoming some of the first known people to reach the summit of the highest peak. During World War II, Ollie and Hank moved around a lot due to Hank’s service in the Navy. After the war, they settled in northern California. 

After they moved, Ollie was unable to obtain a job as an engineer, partially because she was a woman and partially because of the large number of GIs returning home after the war. Ollie established her own machine shop in San Carlos, but sold it in the early 1950’s to start SEPCO, a company that manufactured science education products for middle and high schools. This company thrived and in 1962 she had saved enough to retire and focus fully on her environmental activism and traveling the world. She passed away peacefully in 2013 at 94 years old.

Ollie lived a full and exciting life. Her love of nature drove her to become a dedicated environmentalist and we can still see her impact today.

View of the sunset from Devil’s Slide Trail


County of San Mateo. Devil’s Slide Trail Education Sign. https://www.smcgov.org/parks/devils-slide-trail

DeaneTR. RIP: Olive Mayer 1919-2013. http://deanetr.com/2013/05/12/rip-olive-mayer-1919-2013/

Sierra Club Loma Prieta. Hiker’s Hut. https://www.sierraclub.org/loma-prieta/hikers-hut

Western Friend. Memorials – Olive (Ollie) Graham Hendricks Mayer. https://westernfriend.org/memorials/olive-ollie-graham-hendricks-mayer


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