Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Leslie Lake | Lake | 2483 | Jefferson | 46 17 06 N | 111 53 04 W |
| Leslie Point | Cape | 894 | Fergus | 47 42 55 N | 109 26 02 W |
| Leslie School (historical) | School | 919 | Petroleum | 47 10 18 N | 108 28 57 W |
| Leslie Spring | Spring | 1041 | Powder River | 45 32 12 N | 105 39 45 W |
| Lesofski Homestead | Locale | 1168 | Cascade | 47 12 12 N | 111 59 46 W |
| Lester Number 1 Dam | Dam | 1200 | Carbon | 45 22 48 N | 108 58 27 W |
| Lester Peters Number 1 Dam | Dam | 1043 | Toole | 48 14 18 N | 111 37 03 W |
| Lester Reservoir | Reservoir | 802 | Phillips | 48 58 49 N | 107 30 44 W |
| Lester Well | Well | 718 | Garfield | 47 28 28 N | 106 25 34 W |
| Leta Post Office (historical) | Post Office | 873 | Rosebud | 46 43 47 N | 107 01 27 W |
| Letter Gulch | Valley | | Beaverhead | 45 43 21 N | 112 45 12 W |
| Letz Lake | Lake | 1026 | Pondera | 48 13 55 N | 111 49 33 W |
| Letz Lake Dam | Dam | 1048 | Pondera | 48 13 12 N | 111 49 45 W |
| Letzen Gulch | Valley | | Sanders | 47 42 25 N | 114 41 14 W |
| Leubke School (historical) | School | 643 | Roosevelt | 48 21 35 N | 104 26 02 W |
| Leuck Mine | Mine | 1691 | Madison | 45 27 23 N | 112 08 40 W |
| Leuthold School (historical) | School | 1262 | Stillwater | 45 47 56 N | 109 02 53 W |
| Levalley Creek | Stream | | Custer | 46 29 25 N | 105 29 28 W |
| Levengood Gulch | Valley | | Deer Lodge | 46 09 16 N | 113 00 19 W |
| Levengoods (historical) | Locale | 1672 | Deer Lodge | 46 09 05 N | 112 59 48 W |
| Levengoods Post Office (historical) | Post Office | 1672 | Deer Lodge | 46 09 05 N | 112 59 48 W |
| Levengoods School (historical) | School | 1672 | Deer Lodge | 46 09 05 N | 112 59 48 W |
| Leveque Reservoir Dam | Dam | 1128 | Cascade | 47 14 30 N | 111 29 57 W |
| Leverich Creek | Stream | | Gallatin | 45 35 53 N | 111 02 52 W |
| Leverich School (historical) | School | 1592 | Gallatin | 45 36 21 N | 111 03 10 W |
| Levi Creek | Stream | | Madison | 45 20 21 N | 111 30 48 W |
| Levine Ranch | Locale | 1221 | Lewis and Clark | 47 18 01 N | 112 05 42 W |
| Levings Gulch | Valley | | Lewis and Clark | 46 53 33 N | 112 06 57 W |
| Levinski Creek | Stream | | Gallatin | 45 16 17 N | 111 14 25 W |
| Levinski Ridge | Ridge | 2516 | Gallatin | 45 14 52 N | 111 13 20 W |
| Levitation Ski Trail | Trail | 1810 | Missoula | 47 01 25 N | 113 59 50 W |
| Lew Wallace School (historical) | School | 710 | Sheridan | 48 39 54 N | 104 19 43 W |
| Lewark (historical) | Locale | 1167 | Broadwater | 46 21 47 N | 111 33 02 W |
| Lewarton Coulee | Valley | | Daniels | 48 52 35 N | 105 51 40 W |
| Lewis (historical) | Locale | 1881 | Jefferson | 45 55 28 N | 112 22 31 W |
| Lewis & Clark Caverns State Park | Park | 1504 | Jefferson | 45 50 21 N | 111 53 12 W |
| Lewis and Clark Bridge | Bridge | 600 | Roosevelt | 48 04 00 N | 105 32 07 W |
| Lewis and Clark Camp Hospital | Hospital | 1166 | Lewis and Clark | 46 37 20 N | 112 02 16 W |
| Lewis and Clark Campground | Locale | 1143 | Missoula | 46 46 30 N | 114 23 01 W |
| Lewis and Clark Campground | Locale | 1050 | Toole | 48 32 13 N | 111 51 23 W |
| Lewis and Clark Caverns Campground | Locale | 1302 | Jefferson | 45 49 25 N | 111 51 23 W |
| Lewis and Clark County | Civil | 1549 | Lewis and Clark | 47 02 00 N | 112 29 03 W |
| Lewis and Clark County Cemetery | Cemetery | 1143 | Lewis and Clark | 46 39 23 N | 112 01 51 W |
| Lewis and Clark County Courthouse | Building | 1270 | Lewis and Clark | 46 35 10 N | 112 02 11 W |
| Lewis and Clark County Fairgrounds | Locale | 1175 | Lewis and Clark | 46 37 17 N | 112 03 27 W |
| Lewis and Clark County Poor Farm Cemetery | Cemetery | 1165 | Lewis and Clark | 46 37 25 N | 112 02 18 W |
| Lewis and Clark County Sheriffs Office | Building | 1270 | Lewis and Clark | 46 35 10 N | 112 02 11 W |
| Lewis and Clark Elementary School | School | 1217 | Fergus | 47 03 17 N | 109 25 36 W |
| Lewis and Clark Expedition Campsite Historical Marker | Park | 1321 | Jefferson | 45 52 20 N | 111 57 23 W |
| Lewis and Clark Field | Park | 1492 | Gallatin | 45 40 10 N | 111 02 48 W |
| Lewis and Clark Middle School | School | 979 | Yellowstone | 45 46 54 N | 108 33 00 W |
| Lewis and Clark National Forest | Forest | 2025 | Meagher | 46 54 60 N | 110 38 03 W |
| Lewis and Clark National Forest - Jefferson Division | Forest | 2025 | Meagher | 46 54 60 N | 110 38 03 W |
| Lewis and Clark National Forest - Rocky Mountain Division | Forest | 2289 | Glacier | 47 55 60 N | 112 50 03 W |
| Lewis and Clark National Historic Trail | Trail | 583 | Richland | 48 07 35 N | 104 51 17 W |
| Lewis and Clark Park | Park | 1360 | Gallatin | 45 46 32 N | 111 10 23 W |
| Lewis and Clark Park | Park | 1017 | Ravalli | 46 30 45 N | 114 05 18 W |
| Lewis and Clark Park | Park | 603 | Roosevelt | 48 04 10 N | 105 32 16 W |
| Lewis and Clark Pass | Gap | 1958 | Lewis and Clark | 47 08 34 N | 112 25 44 W |
| Lewis and Clark Picnic Area | Locale | 1158 | Lewis and Clark | 46 36 39 N | 111 42 13 W |
| Lewis and Clark Portage Route Historical Marker | Park | 1065 | Cascade | 47 29 40 N | 111 12 53 W |
| Lewis and Clark Public Library | Building | 1258 | Lewis and Clark | 46 35 07 N | 112 02 31 W |
| Lewis and Clark Range | Range | 2167 | Powell | 47 30 01 N | 113 08 03 W |
| Lewis and Clark School | School | 1058 | Cascade | 47 30 14 N | 111 14 26 W |
| Lewis and Clark School | School | 974 | Missoula | 46 50 40 N | 114 00 11 W |
| Lewis and Clark Shopping Center | Locale | 973 | Missoula | 46 50 15 N | 114 00 38 W |
| Lewis and Clark State Memorial | Park | 886 | Chouteau | 47 48 12 N | 110 39 51 W |
| Lewis and Clark Statue | Park | 1028 | Cascade | 47 29 35 N | 111 18 23 W |
| Lewis and Clark Trail | Trail | 584 | Richland | 47 45 30 N | 104 07 02 W |
| Lewis Avenue School | School | 983 | Yellowstone | 45 46 53 N | 108 34 18 W |
| Lewis Brothers Dam | Dam | 1026 | Fergus | 47 05 06 N | 108 40 03 W |
| Lewis Coulee | Valley | | Cascade | 47 23 11 N | 110 55 18 W |
| Lewis Creek | Stream | | Blaine | 48 09 18 N | 109 13 46 W |
| Lewis Creek | Stream | | Flathead | 47 39 37 N | 113 20 24 W |
| Lewis Creek | Stream | | Lincoln | 48 55 38 N | 114 45 02 W |
| Lewis Creek | Stream | | Madison | 45 01 27 N | 111 57 55 W |
| Lewis Creek | Stream | | Park | 45 18 29 N | 110 55 11 W |
| Lewis Creek | Stream | | Sweet Grass | 45 18 48 N | 110 05 59 W |
| Lewis Dam Number 1 | Dam | 997 | Petroleum | 47 07 18 N | 108 41 51 W |
| Lewis Dam Number 2 | Dam | 1001 | Petroleum | 47 06 60 N | 108 42 09 W |
| Lewis Ditch | Canal | 1365 | Gallatin | 45 44 52 N | 111 15 34 W |
| Lewis Draw | Valley | | Powder River | 45 30 25 N | 106 07 12 W |
| Lewis Gulch | Valley | | Sweet Grass | 45 30 18 N | 110 06 24 W |
| Lewis Hall | Building | 1495 | Gallatin | 45 40 04 N | 111 03 03 W |
| Lewis Junction (historical) | Locale | 1046 | Cascade | 47 24 60 N | 111 09 25 W |
| Lewis Meadow | Flat | 1060 | Flathead | 48 32 32 N | 114 30 34 W |
| Lewis Overflow | Canal | 1334 | Gallatin | 45 47 03 N | 111 18 16 W |
| Lewis Peak | Summit | 1708 | Fergus | 47 13 56 N | 109 07 04 W |
| Lewis Post Office (historical) | Post Office | 1215 | Judith Basin | 47 07 35 N | 110 02 28 W |
| Lewis Post Office (historical) | Post Office | 1359 | Madison | 45 36 60 N | 111 33 43 W |
| Lewis Post Office (historical) | Post Office | 1394 | Meagher | 46 44 30 N | 111 13 03 W |
| Lewis Ranch | Locale | 1555 | Fergus | 46 51 57 N | 109 18 10 W |
| Lewis Range | Range | 2491 | Glacier | 48 52 60 N | 113 51 03 W |
| Lewis Reservoir | Reservoir | 687 | Valley | 47 59 04 N | 106 40 55 W |
| Lewis School (historical) | School | 774 | Dawson | 47 15 33 N | 105 01 43 W |
| Lewis Spring | Spring | 856 | Fergus | 47 38 27 N | 109 00 32 W |
| Lewis-Hudson-Fowler Ditch | Canal | 1617 | Stillwater | 45 23 33 N | 109 40 47 W |
| Lewis-Jenkins Ditch | Canal | 1441 | Madison | 45 30 21 N | 112 17 43 W |
| Lewiston (historical) | Populated Place | 1298 | Jefferson | 46 27 50 N | 111 59 11 W |
| Lewistown | Locale | 1204 | Fergus | 47 03 45 N | 109 25 42 W |
| Lewistown | Populated Place | 1204 | Fergus | 47 03 45 N | 109 25 42 W |
| Lewistown Air Force Station (historical) | Military (Historical) | | Fergus | 47 13 03 N | 109 13 20 W |
| Lewistown City Cemetery | Cemetery | 1209 | Fergus | 47 04 04 N | 109 26 33 W |
| Lewistown Elks Country Club | Locale | 1241 | Fergus | 47 03 25 N | 109 24 13 W |
| Lewistown Fire Station | Building | 1201 | Fergus | 47 03 51 N | 109 25 26 W |
| Lewistown Heights | Populated Place | 1203 | Fergus | 47 04 33 N | 109 27 11 W |
| Lewistown Historical Marker | Park | 1220 | Fergus | 47 04 12 N | 109 23 45 W |
| Lewistown Junction | Populated Place | 1204 | Fergus | 47 03 13 N | 109 24 60 W |
| Lewistown Junior High School | School | 1217 | Fergus | 47 03 40 N | 109 25 60 W |
| Lewistown Municipal Airport | Airport | 1267 | Fergus | 47 02 56 N | 109 28 02 W |