The Bitterroot Public Library Foundation was established in 1989. According to its bylaws, the Foundation is dedicated to “charitable, literary and educational purposes”. The sole purpose of the Foundation is to provide additional money to supplement the library’s tax-based funding.

Contributions to the Bitterroot Public Library Foundation are placed in a permanent fund and prudently invested. The income from the investment is used to help the library offer programs and materials to meet the changing needs and interests of the community beyond basic services.

Funds are raised mainly through donations from their annual fund drive.