Idaho Code § 21-811
It is hereby found, determined, and declared that the creation of a regional airport authority is in all respects for the benefit of the people of the state of Idaho, for the improvement of their welfare and prosperity, and for the promotion of their transportation, and is a public purpose and a matter of statewide concern, and that projects operated by authorities are essential parts of the public transportation system, and that such authorities will be performing essential governmental functions in the exercise of the powers conferred upon them by this act. The state of Idaho declared that authorities shall be required to pay no taxes or assessments upon any of the property acquired by them or under their respective jurisdictions, control, possession, or supervision, or upon the activities of authorities in the operation and maintenance of projects, or upon any charges, fees, revenues, or other income received by authorities except motor vehicle fuel and aviation fuel taxes, and that the bonds and notes of authorities and the income therefrom shall at all times be exempt from taxation.
Idaho Code § 21-811