Neb. Rev. Stat. § 39-1720

Where there is, or may be hereafter constructed, a public bridge across a stream dividing two counties, it shall be the duty of the county boards of such counties to open and keep open within their respective counties a public road leading from such bridge to the most convenient public road. Each county shall bear the expense necessary to open and maintain such roads in good condition for travel. Such roads shall not be closed or vacated except by concurrent action of the county boards of both counties.