He gradually expanded the hut into a large house with a bathing pool and a Japanese garden, where he lived for decades.

David became a military aviator and was killed in a crash during World War I. Ira moved to New York City and became a newspaperman.

Many of his clients paid him in real estate instead of cash, often unloading undeveloped parcels that they considered worthless.

[6] He subdivided the land, put in utilities, planted trees, and sold lots in many neighborhoods including Ocean Beach, Point Loma,[7] Pacific Beach, University Heights, Normal Heights, North Park, East San Diego, and Encanto.

[4] He also bought property in Ramona including five gold mines, and built a country home there on a 240-acre ranch.

[8] As his business prospered he took a leading role in civic affairs, influencing the city's decision about where to purchase water, persuading Glenn H. Curtiss to bring his fledgling aviation company to North Island in Coronado, and helping the city of San Diego gain possession of its tidelands from the state.

Collier chose the central mesa of Balboa Park as the site, selected California Mission as the architectural style, and hired Bertram Goodhue to be the consulting architect.

[9] The theme exhibit, particularly focused on the anthropology of the Southwestern United States, later became the San Diego Museum of Man, of which he was a founder.

By 1914 his business was suffering so badly that he had to resign as president and go back to practicing law and selling real estate.

As a trustee of the defunct Wonderland Amusement Park in Ocean Beach he arranged to sell its exotic animals to the fledgling San Diego Zoo.