W. Va. Code § 22A-2-41: Bonding track used as power conductor.

Where track is used as a power conductor, rails and switches on main entries shall be bonded and cross-bonded in such manner as to assure adequate return. At least one rail on secondary track-haulage roads shall be welded or bonded at every joint, and cross bonds shall be installed at intervals of not more than two hundred feet: Provided, however, That rail joints in such secondary haulage roads need not be bonded where a copper feeder adequate in size parallels the track and is electrically connected thereto at intervals of not more than two hundred feet by cross bonds.