There is no "blade length" restriction of OC of fixed-blade knives in WV State law. There is no ban on carrying daggers, bowie knives, or any other specific blade type for fixed-blade knives.
Technically, you should be withing the law as long as your knife is OC. Concealing a big folder or a fixed-blade knife is restricted/banned however.
Local ordinances may vary though, so check your local municipal codes...