Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Martin School (historical) | School | 815 | Blaine | 48 54 10 N | 109 17 16 W |
| Martin Spring | Spring | 1153 | Carter | 45 50 17 N | 104 28 12 W |
| Martin Spring | Spring | 1783 | Judith Basin | 47 02 47 N | 110 30 25 W |
| Martin Spring | Spring | 1457 | Missoula | 46 57 16 N | 114 27 43 W |
| Martin's Ranch | Locale | 666 | Phillips | 48 31 46 N | 107 29 02 W |
| Martina (historical) | Locale | 1249 | Missoula | 47 13 08 N | 114 38 03 W |
| Martina Creek | Stream | | Missoula | 47 12 53 N | 114 38 25 W |
| Martina Creek Mine | Mine | 1359 | Missoula | 47 12 36 N | 114 39 03 W |
| Martina Mine | Mine | 1645 | Missoula | 47 12 43 N | 114 40 08 W |
| Martina Post Office (historical) | Post Office | 1249 | Missoula | 47 13 08 N | 114 38 03 W |
| Martins Coulee | Valley | | Phillips | 48 36 18 N | 107 39 28 W |
| Martinsdale | Populated Place | 1469 | Meagher | 46 27 30 N | 110 18 48 W |
| Martinsdale (historical) | Locale | 1467 | Meagher | 46 27 35 N | 110 18 50 W |
| Martinsdale Colony | Populated Place | 1446 | Wheatland | 46 29 22 N | 110 16 03 W |
| Martinsdale Colony School | School | 1446 | Wheatland | 46 29 20 N | 110 16 07 W |
| Martinsdale Post Office | Post Office | 1469 | Meagher | 46 27 30 N | 110 18 48 W |
| Martinsdale Reservoir | Reservoir | 1457 | Meagher | 46 27 07 N | 110 16 04 W |
| Martinsdale Reservoir | Reservoir | 1448 | Wheatland | 46 26 36 N | 110 15 27 W |
| Martinsdale Reservoir | Reservoir | 1451 | Wheatland | 46 27 18 N | 110 16 03 W |
| Martinsdale Reservoir Fishing Access Site | Locale | 1458 | Meagher | 46 27 02 N | 110 16 55 W |
| Martinsdale School (historical) | School | 1468 | Meagher | 46 27 33 N | 110 18 47 W |
| Martown Veseth Number 3 Dam | Dam | 812 | Phillips | 47 57 54 N | 108 04 50 W |
| Marty School (historical) | School | 953 | Petroleum | 47 10 48 N | 108 13 22 W |
| Marvell Creek | Stream | | Powder River | 45 37 45 N | 105 52 29 W |
| Marvin Draw | Valley | | Powder River | 45 11 48 N | 105 34 26 W |
| Mary A Mine | Mine | 1737 | Madison | 45 32 12 N | 111 46 13 W |
| Mary Allison Blue Sky Park | Park | 1004 | Toole | 48 30 13 N | 111 51 13 W |
| Mary Aloys | Mine | 2310 | Lewis and Clark | 46 26 03 N | 112 14 36 W |
| Mary Ann Creek | Stream | | Powell | 46 26 28 N | 112 23 32 W |
| Mary Ann Gulch | Valley | | Mineral | 47 04 00 N | 115 02 40 W |
| Mary Ann Mine | Mine | 1287 | Flathead | 47 55 19 N | 114 34 40 W |
| Mary Ann Mine | Mine | 1309 | Flathead | 47 55 18 N | 114 34 28 W |
| Mary B Island | Island | 883 | Lake | 47 55 31 N | 114 10 08 W |
| Mary Baker Lake | Lake | 2013 | Flathead | 48 38 59 N | 113 45 23 W |
| Mary Black Reservoir | Reservoir | 763 | Valley | 48 35 20 N | 106 53 46 W |
| Mary Dam | Dam | 771 | Phillips | 47 37 18 N | 107 46 38 W |
| Mary Dam | Dam | 1093 | Toole | 48 43 06 N | 111 22 03 W |
| Mary Emmee/Clinton Mine | Mine | 2046 | Silver Bow | 46 01 17 N | 112 27 17 W |
| Mary Innes School | School | 1555 | Beaverhead | 45 12 51 N | 112 38 14 W |
| Mary Lake | Lake | 1951 | Mineral | 47 16 20 N | 115 22 43 W |
| Mary Lee Mine | Mine | 1627 | Madison | 45 33 43 N | 111 38 35 W |
| Mary Louise Number 2 Mine | Mine | 1710 | Silver Bow | 46 00 32 N | 112 31 57 W |
| Mary Lynn Hospital (historical) | Hospital | 955 | Liberty | 48 30 38 N | 110 58 03 W |
| Mary P Mine | Mine | 1719 | Lewis and Clark | 47 02 14 N | 112 21 30 W |
| Mary Queen of Heaven Catholic Church | Church | 824 | Mineral | 47 11 41 N | 114 53 19 W |
| Mary Reservoir | Reservoir | 770 | Phillips | 47 37 18 N | 107 46 40 W |
| Mary Reservoir | Reservoir | 1093 | Toole | 48 43 06 N | 111 22 03 W |
| Mary Smith Ranch | Locale | 1212 | Broadwater | 46 25 49 N | 111 26 52 W |
| Maryann Creek | Stream | | Lewis and Clark | 47 10 06 N | 112 42 31 W |
| Maryott Gulch | Valley | | Gallatin | 45 35 49 N | 111 14 24 W |
| Maryott Lake | Lake | 3176 | Carbon | 45 02 54 N | 109 37 31 W |
| Marys Gulch | Valley | | Beaverhead | 45 20 21 N | 113 21 06 W |
| Marys Island | Island | 602 | Richland | 47 23 09 N | 104 22 10 W |
| Marys Knoll | Summit | 1894 | Judith Basin | 46 59 41 N | 110 16 28 W |
| Marys Lamb Dam | Dam | 1086 | Carter | 45 20 30 N | 104 48 44 W |
| Marys Pond | Lake | 1751 | Missoula | 46 42 14 N | 114 21 02 W |
| Marysville | Populated Place | 1650 | Lewis and Clark | 46 45 02 N | 112 18 01 W |
| Marysville (historical) | Locale | 1650 | Lewis and Clark | 46 45 02 N | 112 18 01 W |
| Marysville Cemetery | Cemetery | 1689 | Lewis and Clark | 46 45 24 N | 112 17 28 W |
| Marysville Junction (historical) | Locale | 1436 | Lewis and Clark | 46 45 02 N | 112 14 23 W |
| Marysville Post Office | Post Office | 1648 | Lewis and Clark | 46 45 01 N | 112 17 57 W |
| Marysville School (historical) | School | 1650 | Lewis and Clark | 46 45 02 N | 112 18 02 W |
| Maschetah Post Office (historical) | Post Office | 1109 | Big Horn | 45 49 60 N | 107 10 02 W |
| Maschetah School (historical) | School | 986 | Big Horn | 45 48 18 N | 107 14 50 W |
| Mashesky Reservoir | Reservoir | 866 | Garfield | 47 10 55 N | 107 44 43 W |
| Mason (historical) | Locale | 1021 | Carbon | 45 35 20 N | 108 49 05 W |
| Mason Canal | Canal | 1019 | Carbon | 45 36 16 N | 108 48 36 W |
| Mason Canyon | Valley | | Fergus | 47 16 26 N | 109 27 36 W |
| Mason Canyon Number 1 Mine | Mine | 1631 | Fergus | 47 17 25 N | 109 29 19 W |
| Mason Creek | Stream | | Beaverhead | 45 15 23 N | 113 05 58 W |
| Mason Creek | Stream | | Custer | 46 11 11 N | 105 10 02 W |
| Mason Creek | Stream | | Powder River | 45 43 29 N | 105 10 30 W |
| Mason Creek Bridge | Bridge | 787 | Custer | 46 10 48 N | 105 09 07 W |
| Mason Dam | Dam | 806 | Garfield | 47 27 06 N | 106 46 26 W |
| Mason Ditch | Canal | 1663 | Sweet Grass | 45 34 43 N | 110 07 48 W |
| Mason Gulch | Valley | | Granite | 46 37 08 N | 113 36 10 W |
| Mason Homestead | Locale | 1616 | Sweet Grass | 45 38 30 N | 110 08 56 W |
| Mason Lake | Reservoir | 2525 | Madison | 45 37 39 N | 111 59 34 W |
| Mason Post Office (historical) | Post Office | 2254 | Broadwater | 46 22 02 N | 111 42 23 W |
| Mason Prong | Stream | | Powder River | 45 15 25 N | 105 51 02 W |
| Mason Prong Spring | Spring | 1248 | Powder River | 45 16 02 N | 105 54 42 W |
| Mason Reservoir | Reservoir | 1174 | Powder River | 45 15 36 N | 105 52 50 W |
| Mason School (historical) | School | 1104 | Fergus | 47 20 15 N | 109 51 07 W |
| Mason Spring | Spring | 1130 | Powder River | 45 15 51 N | 105 51 40 W |
| Masonic Cemetery | Cemetery | 1430 | Madison | 45 32 34 N | 112 18 47 W |
| Masonic Home | Locale | 1123 | Lewis and Clark | 46 41 30 N | 111 59 17 W |
| Masonry Peak | Summit | 2165 | Flathead | 48 51 44 N | 114 37 47 W |
| Mass Canyon | Valley | | Beaverhead | 45 06 33 N | 112 41 02 W |
| Mass Creek | Stream | | Meagher | 46 41 11 N | 110 42 54 W |
| Mass Spring | Spring | 755 | Sanders | 47 34 04 N | 115 19 06 W |
| Massa Park | Park | 1171 | Broadwater | 46 19 09 N | 111 31 15 W |
| Massey Creek | Stream | | Teton | 47 57 25 N | 112 48 22 W |
| Mast Ditch | Canal | 2217 | Beaverhead | 45 27 02 N | 112 53 22 W |
| Master Mine | Mine | 2016 | Granite | 46 28 14 N | 113 03 03 W |
| Master Mine | Mine | 1996 | Granite | 46 28 05 N | 113 03 08 W |
| Master Mining Camp | Locale | 2001 | Granite | 46 27 58 N | 113 03 11 W |
| Matador (historical) | Locale | 711 | Blaine | 48 30 34 N | 108 40 03 W |
| Matador Coulee | Valley | | Blaine | 47 58 19 N | 108 51 49 W |
| Matador Ranch | Locale | 904 | Phillips | 47 55 11 N | 108 19 49 W |
| Matador Ranch Number 1 Dam | Dam | 880 | Phillips | 47 51 54 N | 108 16 32 W |
| Matador Ranch Number 10 Dam | Dam | 964 | Phillips | 47 50 12 N | 108 23 50 W |
| Matador Ranch Number 3 Dam | Dam | 894 | Phillips | 47 56 54 N | 108 15 44 W |
| Matador Ranch Number 4 Dam | Dam | 900 | Phillips | 47 54 48 N | 108 19 08 W |
| Matador Ranch Number 6 Dam | Dam | 886 | Phillips | 47 54 48 N | 108 18 08 W |
| Matador Ranch Number 8 Dam | Dam | 883 | Phillips | 47 54 54 N | 108 16 20 W |
| Matahpi Peak | Summit | 2838 | Glacier | 48 42 24 N | 113 38 21 W |
| Mathematics Building | Building | 982 | Missoula | 46 51 34 N | 113 59 08 W |
| Mather Brothers Ranch | Locale | 865 | Custer | 46 40 50 N | 106 04 36 W |
| Mather Number 2 Dam | Dam | 860 | Custer | 46 41 18 N | 106 04 20 W |
| Mathers Dam | Dam | 858 | Custer | 46 40 48 N | 106 03 50 W |