After leaving the Marine Corps, Miller moved to San Francisco to work as a stockbroker. There he met Chonita Bovet. They married in 1960, remaining together until she died 58 years later.
At the time, it was believed that large office buildings were best located in San Francisco rather than on the peninsula to the south. Miller envisioned otherwise. He formed a partnership to develop 24 acres of Bovet family land into an office park with a shopping center. From there, he helped establish Webcor, which under later ownership became a worldwide construction enterprise. He also established the Rusty Scupper restaurant chain. He sold that in 1978. Bearing the same name now, it remains true to his vision. Two years later, Miller founded a bank. He headed it until it was sold 21 years later.
Miller died peacefully Jan. 21, 1019.