Well, stumpage value is really a function of demand, supply, product, species, quality, quantity, distance to markets, logging costs, geographic location, etc. Regardless, geography does play a big part in determining value of standing timber. Since I am unsure about the physical whereabouts of your stand of timber, I can only offer you the following information:
In Illinois, fall 2007 hardwood marketing reports indicate strong white oak demand and price: veneer logs @ $1.50-3.00/bd.ft and sawlogs @ $0.40-1.20/bd.ft. However, Illinois marketing reports indicate weak red oak pricing: veneer and sawlogs @ $0.30-60/bd.ft. [prices are for mill-delivered logs]
However, if your timber physically resides in Pennsylvania, then you would need to contact a PADCNR forester http://www.dcnr.state.pa.us/forestry/contacts.aspx or a local professional consulting forester to determine fair market value for timber in your area.
Hope this helped!