The State of Wisconsin’s Department of Natural Resources is responsible for operating one of the largest state park systems in the United States. Potawatomi State Park, located on the Door County peninsula, consists of about 1,200 acres of flat to gently rolling upland terrain bordered by steep slopes and rugged limestone cliffs along Lake Michigan’s shoreline. A 75-foot observation tower sits atop a 150-foot bluff overlooking Lake Michigan. State officials asked USDA Forest Service researchers to conduct an assessment of the main support timbers of the tower. This report summarizes the results obtained from the inspection and assessment. It includes a brief summary of the nondestructive testing techniques that were used, observations, data from tests conducted on the timbers, and recommendations.