He later became the owner of the Hartsook Inn, a resort in Humboldt County, and two ranches in Southern California on which he reared prized Holstein cattle.

"[1] After graduating from high school at age sixteen Hartsook was apprenticed by his uncle as a civil engineer, but spent most of his time in his father's studio.

[1] Hartsook's success as a photographer and studio owner allowed him to expand into other cities along the Pacific Coast, including San Francisco and Oakland.

[1] Bill Robertson, director of the Los Angeles Bureau of Street Services, cited by KPCC in 2009, mentions 30 studios.

[3] Even if the bulk of the business came from everyday studio portraiture, Hartsook gained prominence through his celebrity clients, which included silent era Hollywood actors such as Mary Pickford, Lillian Gish, and Carlyle Blackwell, other celebrities such as pilot Charles Lindbergh, entrepreneur Henry Ford, and opera singer Geraldine Farrar, and politicians like House leaders Champ Clark and Joseph Gurney Cannon.

In addition to 3,000 acres (12.1 km2) of pastureland at the mouth of Red Rock Canyon in Kern County, Hartsook also owned a 41-acre (0.16 km2) "country home and ranch"[6] in Lankershim (now North Hollywood), where he raised prize-winning purebred Holstein cattle as well as Toggenburg milk goats and "big type Poland China hogs".

[12] Beyond the short-lived postal designation, the Hartsook name is memorialized in a street in the San Fernando Valley, running along the former Lankershim property.

[15] The Hartsook Inn was rebuilt and survived under a succession of owners (and another fire in 1973) until the 1990s, when the last operator sold the property to the Save the Redwoods League after threatening to log the Giant to stave off bankruptcy.