| Mahoning River At Alliance, OH |
| Mahoning River At Leavittsburg, OH |
| Mahoning River At Lowellville, OH |
| Mahoning River At Pricetown, OH |
| Mahoning River Below Berlin Dam Near Berlin Center, OH |
| Mahoning River Below West Ave At Youngstown, OH |
| Massies Creek At Wilberforce, OH |
| Maumee River At Waterville, OH |
| Maumee River Near Defiance, OH |
| Mcguire Creek Near Leesville, OH |
| Middle Branch Nimishillen Creek At Canton, OH |
| Mill Creek At Carthage, OH |
| Mill Creek At Evendale, OH |
| Mill Creek At Fairmount, OH |
| Mill Creek At Garfield Hts, OH |
| Mill Creek At Garfield Pkwy At Garfield Heights, OH |
| Mill Creek At Kemper Road At Sharonville, OH |
| Mill Creek At Reading, OH |
| Mill Creek Near Bellepoint, OH |
| Mill Creek Near Coshocton, OH |
| Monday Creek At Doanville, OH |
| Mosquito Creek Below Mosquito Creek Dam Near Cortland, OH |
| Mosquito Creek Near Greene Center, OH |
| Mud Brook At Cuyahoga Falls, OH |
| Muskingum River At Beverly, OH |
| Muskingum River At Dresden, OH |
| Muskingum River At Mcconnelsville, OH |
| Muskingum River At Zanesville, OH |
| Muskingum River Near Coshocton, OH |
| Nimishillen Creek At North Industry, OH |
| North Fork At Bath Center, OH |
| North Fork Licking River At E. Main St. At Newark, OH |
| North Fork Licking River At Newark, OH |
| North Fork Licking River At Ohio Street, Newark, OH |
| North Fork Licking River At Utica, OH |
| O'Bannon Creek Near Loveland, OH |
| Ohio Brush Creek Near West Union, OH |
| Ohio River Above Sardis, OH |
| Ohio River At Cincinnati, OH |
| Ohio River At Hannibal Lock And Dam (Lower), OH |
| Ohio River At Hannibal Lock And Dam (Upper), OH |
| Ohio River At Marietta, OH |
| Ohio River At New Cumberland Lock & Dam (Lower), OH |
| Ohio River At New Cumberland Lock & Dam (Upper), OH |
| Ohio River At Portsmouth, OH |
| Old Woman Creek At Berlin Rd Near Huron, OH |
| Olentangy River At Claridon, OH |
| Olentangy River Near Delaware, OH |
| Olentangy River Near Worthington, OH |
| Ottawa River At Lima, OH |
