Neb. Rev. Stat. § 81-8,234

(1) The state shall post and maintain a sign at each skatepark and bicycle motocross park sponsored by the state containing the following warning notice: Under Nebraska law, the state is not liable for an injury to or the death of a participant in recreational activities resulting from the inherent risks of the recreational activities pursuant to section 81-8,219 . (2) The absence of a sign shall not give rise to liability on the part of the state.