| Mineral Trust Fund, Permanent Wyoming | Encyclopedia | Sarah Gorin |
| Mission 66 in Yellowstone and Grand Teton Parks | Encyclopedia | John Clayton |
| Mitchell Peak | Field Trips | |
| Mitchell, Finis, Wind River Mountains hiker and conservationist | Encyclopedia | Rebecca Hein |
| Mni Akuwin, Spotted Tail’s daughter | Encyclopedia | Tom Rea |
| Modernization in Wyoming’s national parks | Encyclopedia | John Clayton |
| Moonlight, Thomas | Encyclopedia | Wyoming State Archives |
| Moore, Lucy Morrison | Encyclopedia | John Clayton |
| Morgan, Elliot | Encyclopedia | Wyoming State Archives |
| Mormon Colonizers, Bighorn Basin | Encyclopedia | Darcee Barnes |
| Mormon ferry, North Platte River | Encyclopedia | WyoHistory.org |
| Mormon Handcart Visitors Center | Field Trips | |
| Morris, Alice | Encyclopedia | Robert and Elizabeth Rosenberg |
| Morris, Esther Hobart | Encyclopedia | Abby Dotterer |
| Mother Featherlegs monument | Field Trips | |
| Mount Washburn, Yellowstone National Park | Field Trips | |
| Mountain Shoshone | Encyclopedia | Rebecca Hein |
| Mountain View Historic Hotel & Café | Field Trips | |
| Mountain View Hotel | Encyclopedia | Wyoming State Historic Preservation Office |
| Muir, John in Yellowstone | Encyclopedia | John Clayton |
| Mummy Cave | Field Trips | |
| Murals, Casper Army Air Base | Encyclopedia | Eric Wimmer |
| Murie Center | Field Trips | |
| Murie Family, the: Wilderness Leaders in Wyoming | Encyclopedia | Emilene Ostlind |
| Murie, Adolph | Encyclopedia | Emilene Ostlind |
| Murie, Louise | Encyclopedia | Emilene Ostlind |
| Murie, Mardy | Encyclopedia | Emilene Ostlind |
| Murie, Olaus | Encyclopedia | Emilene Ostlind |
| Museum of the American West | Field Trips | |
| Museum of the Fur Trade | Field Trips | |
| Museum of the Mountain Man | Field Trips | |
| Nagle Warren Mansion | Field Trips | |
| Names Hill | Field Trips | |
| Names Hill, Oregon Trail Inscription Site | Encyclopedia | WyoHistory.org |
| Nancy Hill Grave | Field Trips | |
| Narrows, The, Oregon Trail landmark on the Sweetwater River | Encyclopedia | WyoHistory.org |
| National Bighorn Sheep Center | Field Trips | |
| National Elk Refuge | Field Trips | |
| National Historic Trails Interpretive Center | Field Trips | |
| Native American geography in Wyoming | Encyclopedia | Gregory Nickerson |
| Native American trade before European arrival | Encyclopedia | Samuel Western |
| Natrona County, Wyoming | Encyclopedia | Rebecca A. Hunt |
| Nelson, Aven, longtime University of Wyoming botanist | Encyclopedia | Lori Van Pelt |
| Nelson, S.A., Powell banker | Encyclopedia | Tom Rea |
| New Fork River crossing | Field Trips | |
| New Fork River Crossing | Encyclopedia | Clint Gilchrist |
| Newcastle Chamber of Commerce | Field Trips | |
| Newcastle, Wyoming | Encyclopedia | Nicole Lebsack |
| Newspapers, Jackson Hole | Encyclopedia | Kerry Drake |
| Newspapers, Jackson Hole, photo controversy | Encyclopedia | Kerry Drake |
