His distinctive Spanish Colonial Revival style — reflected in the post office, the Lucie Stern Community Center, buildings downtown and hundreds of homes — helped to define the image of Palo Alto.
Clark got his start around 1919, assisting in his father's collaboration with Lou Henry Hoover in designing a home on the Stanford University campus for the future president and first lady.
Besides the Hoover House, now the official residence of the Stanford University president, Clark's legacy includes 98 Palo Alto homes — including the Lucie Stern House at 1950 Cowper St.— and 39 campus residences.
Other notable works include commercial buildings on the 500 block of Ramona Street, the old Charles and Kathleen Norris house at 1247 Cowper and many of the homes on Coleridge Avenue between Cowper and Webster streets.
"I used to go down to the building inspector's office, lay my plan down and hack things out in a half-hour," Clark said in a 1979 interview with the Weekly.
"Now there are so many reports to file it can take months. That is not all bad, but it sure has made the practice of architecture more complicated."
Clark, who died in 1989, was born in San Francisco in 1893 and graduated from Palo Alto High School in 1910 and from Stanford, with degrees in art and engineering, in 1914. He earned a master's in architecture from Columbia University in 1917.
He once recalled that 38 of his 41 high school classmates went on to Stanford, where there was no tuition and where Paly graduates — many, like Clark, the children of professors — were welcomed.
Clark's younger sister, Esther Clark, was one of the first pediatricians in Palo Alto, an early member of the Palo Alto Medical Clinic (now the Palo Alto Medical Foundation) and the founder of the nonprofit Children's Health Council.
Clark was the only architect with an office in Palo Alto between 1922 and 1930 and, as the city grew, his business and reputation boomed. He taught at Stanford from 1950 to 1972.
"We had a terrific start on everyone," Clark told the Weekly. "I was just like a country doctor. I did a little bit of everything because there was so much to do.
"I've always been happy in this business. It's rewarding, and I can see the effect of my work. And there aren't too many hardships.
"You know they say a doctor buries his mistakes, and a lawyer's mistakes go to prison. All an architect has to do to avoid his mistakes is drive around the block."
More than 30 of Clark's buildings are on the City of Palo Alto's inventory of historic buildings and three — including the Hamilton Post Office — are on the National Register of Historic Places.