i took my wife mabel to markland dam on the ohio river monday fishin , we launched above the dam at craigs creek on the kentucky side and i cast netted several shad there before heading down river to the dam . mabel had never locked thru and i thought she would enjoy it . other than waiting in the heat of the day for the lockmaster to open the gate she did , it took about twenty minutes to get in the lock . when you aproach the dam from up river theres two locks one on the left or outside and one on the right or inside , the inside is for barge traffic and the outside is for pleasure or fishing boats , on the end of the wall of the outside lock is a chain with a sign that reads (pull chain for service ) this lets the lockmaster know you want to lock thru and he will prepare the lock for you if the water is at the lower pool stage you will have to wait for him to bring the water up to your level and open the gates to let any boats that are in out and you in , its always best to let them out so as you will have a place to tie off , once inside you will find several places to tie your boat but be forwarned tie off to the floating bouey's and not the wall :lol: when mabel and i got in the lock i showed her where we were to tie off and why , id hate to see a boat hanging from the wall but im sure america's funniest video's would pay well :lol: any way my fish finder showed 54.6 feet the gates closed and the water started to drop , on the wall on either side of the bouey is steel bumpers to protect the wall from boat damage these bumpers are two feet apart as the boat went down with the water mabel counted the bumpers of course i just looked at the fish finder , at the bottom it read 14 foot she was shocked that the gates and dam were holding back that much water at 40 feet above us . below are pics of the bouey and bumpers and the gates from the inside of the lock i hope yall enjoy as much as mabel did .