The Pennsylvania Fish Commsision has launched an intensive survey at Beltzville State Park and findings thus far reveal the presence of very large fish in the 947-acre lake. Fritz Ohlsen, Jim Thorpe, the Fish Commission's waterways patrolman in Carbon County, told members of the county's Conservation District that the study indicates the existence of 20-inch walleyes in the immense body of water, which extends from the breast of the dam in Franklin Township, a distance of about seven miles to Trachsville.