16 Pa. Stat. § 8551
Bridges over any river, creek, or rivulet, being on the line of adjoining counties, or located within one-fourth of a mile therefrom, and necessary for the accommodation of the inhabitants of both counties, shall be authorized in the manner provided in the case of other county bridges, except that the court of quarter sessions of each county shall appoint three of the viewers, and that a report as aforesaid be made to the said courts, respectively, and that the said courts shall, together with the grand juries and commissioners of the respective counties, in all other respects have and exercise a concurrent jurisdiction and discretion therein: Provided, however, That nothing herein contained shall prevent any county in this Commonwealth from erecting a bridge at any point wholly within the limits of said county, without any view, or other proceedings whatsoever, in any adjoining county.
16 P.S. § 8551