Insurance for townships is available through the North Dakota Insurance Reserve Fund (NDIRF).
NDIRF is not a state agency, it is an insurance company started by the government subdivisions of North Dakota. It is not state-funded, it operates on the premiums paid by policyholders.
Much of the coverage NDIRF provides is not otherwise available to local governments, what is available from other providers is very costly.
Without NDIRF townships could not afford liability insurance, no other company wants to provide liability insurance to local governments.