D was open to the public, and in exchange for a fee patrons were invited to ski, snowboard, and snowtube. P brought his three children and another child to D to snowtube. D's only restriction was that only persons at least six years old or forty-four inches tall were eligible to participate. Patrons were required to sign a 'Waiver, Defense, Indemnity and Hold Harmless Agreement, and Release of Liability' (agreement). P read and signed the agreement on behalf of himself and the four children. P's right foot became caught between his snowtube and the man-made bank of the snowtubing run, resulting in serious injuries that required multiple surgeries to repair. P sued for negligence. Ds moved for summary judgment, claiming that the agreement barred P's negligence claim as a matter of law. It was granted. This appeal followed.