Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Peterson Ranch Airport | Airport | 1015 | Chouteau | 47 36 29 N | 110 54 22 W |
| Peterson Reservoir Dam | Dam | 869 | Rosebud | 46 12 24 N | 106 24 20 W |
| Peterson School (historical) | School | 1364 | Cascade | 47 15 35 N | 110 58 53 W |
| Peterson School (historical) | School | 1223 | Stillwater | 45 51 24 N | 109 05 26 W |
| Peterson School (historical) | School | 1085 | Toole | 48 46 59 N | 111 36 04 W |
| Peterson Spring | Spring | 978 | Garfield | 46 57 29 N | 107 28 25 W |
| Petes Bend | Bend | 973 | Carter | 45 23 38 N | 104 03 49 W |
| Petes Canyon | Valley | | Carbon | 45 07 59 N | 108 11 05 W |
| Petes Coulee | Valley | | Treasure | 46 09 17 N | 107 26 09 W |
| Petes Point | Summit | 1616 | Mineral | 47 24 18 N | 115 32 12 W |
| Petes Spring | Spring | 1329 | Carbon | 45 08 51 N | 108 12 35 W |
| Petitt Dam | Dam | 822 | Garfield | 47 05 18 N | 106 33 20 W |
| Petranek Dam | Dam | 957 | Fergus | 47 26 36 N | 109 05 09 W |
| Petranek Reservoir Dam | Dam | 938 | Fergus | 47 27 42 N | 109 05 21 W |
| Petri Dam | Dam | 903 | Blaine | 48 57 12 N | 108 26 38 W |
| Petrie Post Office (historical) | Post Office | 903 | Blaine | 48 59 27 N | 108 19 15 W |
| Petrie School (historical) | School | 903 | Blaine | 48 59 11 N | 108 18 06 W |
| Petroglyph Canyon | Valley | | Carbon | 44 58 08 N | 108 28 01 W |
| Petroleum County | Civil | 955 | Petroleum | 47 09 00 N | 108 16 02 W |
| Petroleum County Courthouse | Building | 899 | Petroleum | 47 00 15 N | 108 20 56 W |
| Petroleum County Public Library | Building | 900 | Petroleum | 47 00 06 N | 108 21 08 W |
| Petroleum County Sheriffs Department | Building | 900 | Petroleum | 47 00 11 N | 108 21 03 W |
| Petrolia Dam | Dam | 884 | Petroleum | 46 56 24 N | 108 14 32 W |
| Petrolia Lake | Reservoir | 884 | Petroleum | 46 56 07 N | 108 14 38 W |
| Petrolia Post Office (historical) | Post Office | 846 | Petroleum | 46 57 60 N | 108 06 05 W |
| Petrolia School (historical) | School | 845 | Petroleum | 46 57 33 N | 108 05 42 W |
| Pettapiece Badland | Area | 1242 | Cascade | 47 16 09 N | 111 19 24 W |
| Pettengill Creek | Stream | | Beaverhead | 45 38 30 N | 113 03 37 W |
| Petter Memorial Mennonite Church | Church | 1023 | Rosebud | 45 37 12 N | 106 39 52 W |
| Pettersen Number 1 Dam | Dam | 628 | Dawson | 47 09 48 N | 104 41 44 W |
| Petterson School (historical) | School | 955 | Rosebud | 46 41 59 N | 106 35 34 W |
| Petticoat Junction Dam | Dam | 1145 | Fergus | 47 13 30 N | 109 32 21 W |
| Petty Creek | Stream | | Lewis and Clark | 47 23 08 N | 112 40 38 W |
| Petty Creek | Stream | | Meagher | 46 49 35 N | 110 41 55 W |
| Petty Creek | Stream | | Missoula | 46 59 32 N | 114 26 49 W |
| Petty Creek (historical) | Locale | 903 | Missoula | 46 59 30 N | 114 26 48 W |
| Petty Creek Fishing Access Site | Locale | 913 | Missoula | 46 59 27 N | 114 26 08 W |
| Petty Crown Creek Trail | Trail | 2118 | Lewis and Clark | 47 22 31 N | 112 46 44 W |
| Petty Ford Creek Trail | Trail | 1743 | Lewis and Clark | 47 23 56 N | 112 42 42 W |
| Petty Mountain | Summit | 2212 | Missoula | 46 54 41 N | 114 24 20 W |
| Petzold Ranch | Locale | 1649 | Meagher | 46 19 11 N | 110 44 56 W |
| Pew Gulch | Valley | | Sanders | 48 00 51 N | 115 59 25 W |
| Peyote Point | Summit | 2200 | Big Horn | 45 07 53 N | 107 55 24 W |
| Peyton Creek | Stream | | Ravalli | 45 44 43 N | 114 25 41 W |
| Peyton Rock | Pillar | 1724 | Ravalli | 45 44 56 N | 114 25 59 W |
| Pfaff Irrigation Dam | Dam | 859 | Prairie | 46 52 48 N | 105 59 02 W |
| Pfaft Number 1 Dam | Dam | 923 | Prairie | 46 53 30 N | 105 57 38 W |
| Phantom Coulee Reservoir Dam | Dam | 941 | Chouteau | 47 35 60 N | 110 08 33 W |
| Phantom Creek | Stream | | Stillwater | 45 12 18 N | 109 41 20 W |
| Phantom Glacier | Glacier | 3160 | Carbon | 45 09 15 N | 109 44 40 W |
| Phantom Lake | Lake | 2839 | Stillwater | 45 11 43 N | 109 43 38 W |
| Pharmacy/Psychology Building | Building | 982 | Missoula | 46 51 30 N | 113 59 08 W |
| Pheasant Creek | Stream | | Lincoln | 48 49 16 N | 115 50 08 W |
| Pheasant Point | Summit | 1208 | Lincoln | 48 17 59 N | 115 49 18 W |
| Pheasant Run Park | Park | 1017 | Missoula | 46 49 22 N | 114 02 31 W |
| Phebus Trailer Court | Locale | 916 | Fallon | 46 21 14 N | 104 16 34 W |
| Phelan Home School (historical) | School | 1387 | Blaine | 48 10 18 N | 109 31 13 W |
| Phellps School (historical) | School | 810 | Sheridan | 48 43 04 N | 104 59 50 W |
| Phelps Creek | Stream | | Park | 45 01 49 N | 110 41 53 W |
| Phelps Ditch | Canal | 1299 | Stillwater | 45 31 37 N | 109 33 37 W |
| Phil Creek | Stream | | Flathead | 47 37 16 N | 113 19 37 W |
| Philbrick Number 3 Dam | Dam | 898 | Rosebud | 46 00 42 N | 106 29 20 W |
| Philbrick School (historical) | School | 867 | Rosebud | 45 54 40 N | 106 23 14 W |
| Philbrook (historical) | Populated Place | 1291 | Judith Basin | 46 59 08 N | 109 58 26 W |
| Philbrook Cemetery | Cemetery | 1291 | Judith Basin | 46 58 59 N | 109 57 24 W |
| Philbrook School (historical) | School | 1291 | Judith Basin | 46 58 60 N | 109 57 03 W |
| Philips Dam | Dam | 1005 | Phillips | 47 49 36 N | 108 37 51 W |
| Philips School (historical) | School | 1262 | Fergus | 47 09 44 N | 109 28 01 W |
| Philipsburg | Locale | 1582 | Granite | 46 19 58 N | 113 18 13 W |
| Philipsburg | Populated Place | 1598 | Granite | 46 19 56 N | 113 17 39 W |
| Philipsburg Bay | Bay | 1945 | Granite | 46 12 30 N | 113 17 05 W |
| Philipsburg Bay Campground | Locale | 1954 | Granite | 46 12 23 N | 113 17 27 W |
| Philipsburg Cemetery | Cemetery | 1620 | Granite | 46 20 28 N | 113 17 52 W |
| Philipsburg Community Church | Church | 1577 | Granite | 46 20 16 N | 113 18 24 W |
| Philipsburg Post Office | Post Office | 1598 | Granite | 46 19 56 N | 113 17 39 W |
| Philipsburg Public Library | Building | 1603 | Granite | 46 19 57 N | 113 17 37 W |
| Philipsburg Schools | School | 1609 | Granite | 46 19 44 N | 113 17 46 W |
| Philipsburg Valley | Valley | | Granite | 46 21 35 N | 113 19 14 W |
| Phillipi Creek | Stream | | Powder River | 45 26 12 N | 105 23 04 W |
| Phillipine Coulee | Valley | | Liberty | 48 37 45 N | 111 00 55 W |
| Phillippi Number 1 Dam | Dam | 1076 | Carter | 45 19 42 N | 104 48 50 W |
| Phillippi Reservoir | Reservoir | 1078 | Carter | 45 19 31 N | 104 49 21 W |
| Phillips | Populated Place | 775 | Phillips | 48 05 37 N | 108 09 50 W |
| Phillips Butte | Summit | 1265 | Powder River | 45 16 04 N | 105 58 35 W |
| Phillips Buttes | Summit | 881 | Garfield | 47 01 41 N | 106 35 16 W |
| Phillips Coulee | Valley | | Fergus | 47 32 34 N | 108 33 46 W |
| Phillips County | Civil | 729 | Phillips | 48 12 00 N | 107 56 02 W |
| Phillips County Cemetery | Cemetery | 690 | Phillips | 48 21 07 N | 107 51 47 W |
| Phillips County Courthouse | Building | 688 | Phillips | 48 21 26 N | 107 52 42 W |
| Phillips County Fairground | Locale | 698 | Phillips | 48 23 58 N | 108 14 37 W |
| Phillips County Family Health Clinic | Hospital | 687 | Phillips | 48 21 28 N | 107 51 33 W |
| Phillips County Good Samaritan Retirement Center | Hospital | 687 | Phillips | 48 21 28 N | 107 51 33 W |
| Phillips County Hospital | Hospital | 687 | Phillips | 48 21 24 N | 107 52 02 W |
| Phillips County Museum | Building | 687 | Phillips | 48 21 35 N | 107 52 37 W |
| Phillips County Public Library | Building | 688 | Phillips | 48 21 24 N | 107 52 25 W |
| Phillips County Sheriffs Department | Building | 688 | Phillips | 48 21 26 N | 107 52 42 W |
| Phillips Creek | Stream | | Garfield | 47 02 45 N | 106 37 11 W |
| Phillips Creek | Stream | 770 | Lincoln | 48 58 17 N | 115 06 20 W |
| Phillips Creek | Stream | | Pondera | 48 08 35 N | 112 53 12 W |
| Phillips Ditch | Canal | 1575 | Madison | 45 18 04 N | 112 06 04 W |
| Phillips Ditch | Canal | 1543 | Stillwater | 45 23 04 N | 109 34 25 W |
| Phillips Post Office (historical) | Post Office | 775 | Phillips | 48 05 37 N | 108 09 50 W |
| Phillips Power Plant (historical) | Building | 718 | Blaine | 47 44 26 N | 108 54 12 W |
| Phillips Ranch | Locale | 1184 | Carbon | 45 19 33 N | 108 59 41 W |
| Phillips Reservoir | Reservoir | 1005 | Phillips | 47 49 35 N | 108 38 03 W |
| Phillips Reservoir | Reservoir | 1073 | Powder River | 45 32 43 N | 105 59 26 W |
| Phillips School (historical) | School | 775 | Phillips | 48 06 05 N | 108 10 17 W |
| Phillips Well | Well | 1067 | Powder River | 45 23 15 N | 105 59 24 W |
| Phills Lake | Lake | 890 | Lincoln | 48 51 24 N | 115 12 08 W |
| Phipps Post Office (historical) | Post Office | 843 | Hill | 48 57 10 N | 109 29 60 W |