| 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 |
| Nichols, Lora Webb, photographer | Encyclopedia | Lori Van Pelt |
| Nicolaysen Art Museum & Discovery Center | Field Trips | |
| Nineteenth Amendment, ratification of by Wyoming | Encyclopedia | Rebecca Hein |
| Ninth Crossing, Sweetwater River | Encyclopedia | WyoHistory.org |
| Niobrara County, Wyoming | Encyclopedia | Nicole Lebsack |
| North Platte River Basin | Encyclopedia | Emilene Ostlind |
| North Platte River crossings; Oregon Trail sites of | Encyclopedia | WyoHistory.org |
| Northern Arapaho Tribe, 1905 Land Cession Agreement | Encyclopedia | WyoHistory.org |
| Northern Arapaho, arrival of on Shoshone Reservation, 1878 | Encyclopedia | WyoHistory.org |
| Northern Utilities, Casper Star-Tribune and | Encyclopedia | Kerry Drake |
| Nye, Bill, 1880s Laramie Boomerang editor and humorist | Encyclopedia | Charles E. Rankin |
| Obsidian Cliffs | Field Trips | |
| Occidental Hotel | Field Trips | |
| Odd Fellows Building, Casper | Encyclopedia | Stephanie Lowe |
