Grants are an excellent funding opportunity for libraries. Typically, they focus on specific projects such as a program or collection development and will not cover construction, operating costs, or staffing. Below are a collection of areas to look for grants of all sizes and levels. Make sure to check for grants periodically as some are open at different times of the year.
Grants available from North Dakota agencies:
Many organizations that cover a broad area of the state or country are willing to fund library projects--specifically, consider looking at local telecommunications or electric cooperatives for opportunities. On their websites, it's often framed as "giving back to the communities" they serve. Many ND libraries receive almost annual grants from their regional providers.