Just found the Pa law on fencing
Road fences of wire with or without barbs
It shall and is hereby declared to be lawful for any land owner within this Commonwealth to construct, build and maintain, along any of the highways of this Commonwealth, fences made in whole or in part of wire, with or without barbs, subject at all times to such restrictions and prohibitions as may be imposed by the municipal authorities relative thereto.
1899, May 2, P.L. 163, § 1. Amended 1976, April 7, P.L. 71, No. 31, § 1, imd. effective.
§ 32. Wire fences, with or without barbs, declared legal
A fence, in whole or in part of wire, with or without barbs, is hereby declared to be a legal and lawful fence, within the meaning and provisions of any act of the Legislature of this State relative to the building, constructing and maintaining of line fences, provided that such wire fence shall be of the height required by such act or acts. All statutes and parts of statutes inconsistent herewith be and the same are hereby repealed.