The Hood House is situated in Los Guilucos Valley, popularly known as the Valley of the Moon. It is the only existing brick building from the pre-Civil War era in Sonoma County. Its original owner, William Hood, was among the state's early settlers and is noted for introducing affluent living to the area.

From 1905 to 1918, the Hood House was a summer residence for former United States Senator Thomas Kearns of Utah, who reestablished the mansion as a hub of social activity in Sonoma County. Ex-Presidents Ulysses S. Grant, William McKinley, and Theodore Roosevelt are believed to have been among Kearns' distinguished guests.

The Hood House was nominated for the National Register because of its association with the Knights of Pythias who purchased the property in 1924 as a home for its elderly members. The Knights of Pythias was at the height of its popularity with nearly one million members nationwide.

Approximately 30 million of the 60 million people in the United States (1920 census) claimed membership in a fraternal group. As the cornerstone of the California Pythian Home, the Hood House represents a bygone era when fraternal benevolence and mutual aid provided the only economic security for millions of Americans.

Dwindling membership forced the Knights to sell the property to the State of California in 1944. The property became the Los Guilucos School for Girls.

The Hood House was dedicated as California Historical Landmark 692 in 1959.

In 1974, the property was purchased by Sonoma County.

Adapted from the NRHP nomination submitted in 1997.