Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Yellow Water Dike | Dam | 949 | Petroleum | 46 54 12 N | 108 28 14 W |
| Yellow Water Main Dam | Dam | 954 | Petroleum | 46 54 18 N | 108 28 14 W |
| Yellow Water Reservoir | Reservoir | 950 | Petroleum | 46 54 08 N | 108 28 21 W |
| Yellow Water School (historical) | School | 971 | Petroleum | 46 55 17 N | 108 32 22 W |
| Yellowjacket Creek | Stream | | Powell | 47 10 57 N | 113 09 43 W |
| Yellowstone (historical) | Locale | 2032 | Gallatin | 44 39 30 N | 111 06 18 W |
| Yellowstone Airport | Airport | 2023 | Gallatin | 44 41 18 N | 111 07 06 W |
| Yellowstone Baptist College | School | 987 | Yellowstone | 45 44 29 N | 108 36 57 W |
| Yellowstone Bible Encampment | Locale | 1711 | Park | 45 18 05 N | 110 33 38 W |
| Yellowstone Camp | Locale | 2075 | Ravalli | 46 07 37 N | 113 57 16 W |
| Yellowstone Canal | Canal | 798 | Treasure | 46 17 10 N | 107 00 51 W |
| Yellowstone City (historical) | Locale | 1636 | Park | 45 19 15 N | 110 42 33 W |
| Yellowstone Community Church | Church | 608 | Richland | 47 27 09 N | 104 20 36 W |
| Yellowstone Coulee | Valley | | Prairie | 46 42 30 N | 105 28 49 W |
| Yellowstone County | Civil | 915 | Yellowstone | 45 55 00 N | 108 18 02 W |
| Yellowstone Crossing Post Office (historical) | Post Office | 1359 | Park | 45 41 25 N | 110 31 48 W |
| Yellowstone Edge RV Park | Locale | 1523 | Park | 45 24 50 N | 110 42 28 W |
| Yellowstone Gateway Mall | Locale | 1381 | Park | 45 39 18 N | 110 34 18 W |
| Yellowstone Mine | Mine | 2131 | Meagher | 46 28 23 N | 110 41 11 W |
| Yellowstone Mine | Mine | 2138 | Meagher | 46 28 22 N | 110 41 12 W |
| Yellowstone National Park County (historical) | Civil | 2508 | Park | 45 01 60 N | 110 58 03 W |
| Yellowstone Park KOA Campground | Locale | 2031 | Gallatin | 44 41 15 N | 111 14 26 W |
| Yellowstone Plateau | Area | 2264 | Beaverhead | 45 17 36 N | 113 00 38 W |
| Yellowstone River Bridge | Bridge | 1592 | Park | 45 01 56 N | 110 42 20 W |
| Yellowstone River Bridge | Bridge | 647 | Prairie | 46 51 20 N | 105 06 59 W |
| Yellowstone River Historical Marker | Park | 684 | Dawson | 46 53 54 N | 105 01 10 W |
| Yellowstone River Trout Hatchery | Locale | 1232 | Sweet Grass | 45 50 10 N | 109 57 36 W |
| Yellowstone Valley Youth Clinic | Hospital | 720 | Custer | 46 24 41 N | 105 50 04 W |
| Yellowstone-Bighorn Research Camp | Locale | 2079 | Carbon | 45 07 19 N | 109 16 23 W |
| Yellowtail Afterbay Dam | Dam | 978 | Big Horn | 45 19 06 N | 107 55 26 W |
| Yellowtail Afterbay Reservoir | Reservoir | 978 | Big Horn | 45 19 06 N | 107 55 26 W |
| Yellowtail Dam | Dam | 1114 | Big Horn | 45 18 24 N | 107 57 29 W |
| Yemen | Locale | 1010 | Chouteau | 47 42 30 N | 110 43 33 W |
| Yemen Post Office (historical) | Post Office | 1010 | Chouteau | 47 42 30 N | 110 43 33 W |
| Yesterdays Playthings Doll and Toy Museum | Building | 1381 | Powell | 46 23 33 N | 112 44 10 W |
| Yew Creek | Stream | | Lake | 47 55 21 N | 113 53 06 W |
| YMCA Camp Child | Locale | 1599 | Powell | 46 31 27 N | 112 23 33 W |
| Ynot (historical) | Populated Place | 742 | Phillips | 48 50 12 N | 107 40 34 W |
| Ynot Post Office (historical) | Post Office | 742 | Phillips | 48 50 12 N | 107 40 34 W |
| Yoakum Spring | Spring | 1061 | Garfield | 46 54 54 N | 107 02 13 W |
| Yodeling Valley Dam | Dam | 743 | Richland | 47 39 42 N | 104 57 50 W |
| Yodlin Creek | Stream | | Lincoln | 48 50 21 N | 115 36 25 W |
| Yogo Creek | Stream | | Judith Basin | 46 50 45 N | 110 18 38 W |
| Yogo Crossing | Populated Place | 1559 | Judith Basin | 46 51 20 N | 110 18 60 W |
| Yogo Peak | Summit | 2685 | Judith Basin | 46 55 37 N | 110 32 44 W |
| Yogo Post Office (historical) | Post Office | 1837 | Judith Basin | 46 55 15 N | 110 27 10 W |
| Yogo Ski Trail | Trail | 2326 | Meagher | 46 50 19 N | 110 42 32 W |
| Yonkee Cutoff | Locale | 1197 | Powder River | 45 09 38 N | 106 03 04 W |
| York | Populated Place | 1212 | Lewis and Clark | 46 43 18 N | 111 45 07 W |
| York Bridge Fishing Access Site | Locale | 1122 | Lewis and Clark | 46 42 48 N | 111 48 14 W |
| York Cemetery | Cemetery | 1256 | Lewis and Clark | 46 43 22 N | 111 45 13 W |
| York Draw | Valley | | Carter | 45 34 53 N | 104 51 25 W |
| York Gulch | Valley | | Deer Lodge | 45 48 19 N | 113 21 15 W |
| York Gulch | Valley | | Lewis and Clark | 46 42 51 N | 111 43 56 W |
| York Island | Island | 712 | Garfield | 47 55 48 N | 106 27 58 W |
| York Post Office (historical) | Post Office | 1212 | Lewis and Clark | 46 43 18 N | 111 45 07 W |
| York Reservoir | Reservoir | 818 | Garfield | 47 14 23 N | 106 41 24 W |
| York Reservoir | Reservoir | 809 | Valley | 48 36 56 N | 107 05 17 W |
| York Reservoir Dam | Dam | 819 | Garfield | 47 14 24 N | 106 41 26 W |
| York School (historical) | School | 1212 | Lewis and Clark | 46 43 18 N | 111 45 07 W |
| Yorks Islands | Island | 1176 | Broadwater | 46 15 45 N | 111 29 28 W |
| Yost Ranch | Locale | 1302 | Sweet Grass | 45 50 29 N | 110 02 56 W |
| Youderian Coulee | Valley | | Garfield | 46 49 09 N | 107 47 13 W |
| Young America Mine | Mine | 1961 | Granite | 46 19 16 N | 113 15 25 W |
| Young Clemons Dam | Dam | 1255 | Teton | 47 34 42 N | 112 22 51 W |
| Young Coulee | Valley | | McCone | 47 45 29 N | 105 50 30 W |
| Young Creek | Stream | | Lincoln | 48 58 09 N | 115 10 44 W |
| Young Creek | Stream | | Sanders | 47 47 47 N | 115 06 09 W |
| Young Man Lake | Lake | 2107 | Glacier | 48 29 60 N | 113 27 07 W |
| Young Number 1 Dam | Dam | 731 | Custer | 46 31 54 N | 105 20 50 W |
| Young School (historical) | School | 847 | Phillips | 48 34 02 N | 108 03 48 W |
| Young School (historical) | School | 747 | Prairie | 46 45 01 N | 105 15 36 W |
| Young Springs | Spring | 1618 | Beaverhead | 45 28 52 N | 112 43 51 W |
| Young Sun Dam | Dam | 1295 | Teton | 47 37 24 N | 112 27 21 W |
| Young-Pickering Ditch | Canal | 1105 | Carbon | 45 29 38 N | 108 55 03 W |
| Youngquist Mine | Mine | 795 | McCone | 47 25 32 N | 105 44 19 W |
| Youngs Coulee | Valley | | Richland | 47 38 54 N | 104 13 52 W |
| Youngs Creek | Stream | | Big Horn | 44 58 09 N | 106 54 35 W |
| Youngs Creek | Stream | | Meagher | 46 17 38 N | 110 43 06 W |
| Youngs Creek | Stream | | Powell | 47 26 44 N | 113 11 01 W |
| Youngs Creek Ford | Locale | 1436 | Powell | 47 26 44 N | 113 11 01 W |
| Youngs Creek School (historical) | School | 1208 | Big Horn | 45 01 50 N | 106 55 37 W |
| Youngs Island | Island | 594 | Sheridan | 48 27 49 N | 104 26 47 W |
| Youngs Mountain | Summit | 2565 | Powell | 47 16 42 N | 113 15 05 W |
| Youngs Pass | Gap | 2093 | Powell | 47 14 56 N | 113 15 42 W |
| Youngs Point | Locale | 1046 | Stillwater | 45 36 44 N | 109 00 28 W |
| Youngs Point | Summit | 1245 | Carbon | 45 35 59 N | 108 59 49 W |
| Youngstrom Ranch | Locale | 1633 | Carbon | 45 16 39 N | 109 27 17 W |
| Your Name Dam | Dam | 721 | Valley | 47 55 48 N | 106 57 32 W |
| Your Name Reservoir | Reservoir | 720 | Valley | 47 55 50 N | 106 57 23 W |
| Yourname Creek | Stream | | Powell | 46 54 01 N | 113 04 23 W |
| Youst Ditch | Canal | 1174 | Carbon | 45 07 49 N | 109 00 05 W |
| Yreka | Populated Place | 1396 | Missoula | 46 51 41 N | 113 19 51 W |
| Yreka Post Office (historical) | Post Office | 1396 | Missoula | 46 51 41 N | 113 19 51 W |
| Yucca Golf Club | Locale | 1028 | Cascade | 47 15 49 N | 111 42 11 W |
| Yukon Creek | Stream | | Lewis and Clark | 47 01 04 N | 112 46 06 W |
| Yukon Jack Dam | Dam | 923 | Blaine | 48 21 60 N | 109 01 33 W |
| Yukon Mine | Mine | 1254 | Flathead | 48 23 07 N | 114 44 09 W |
| Yukon Saddle | Populated Place | 1581 | Missoula | 46 42 35 N | 113 48 50 W |
| Yule School (historical) | School | 1549 | Cascade | 47 03 05 N | 110 48 56 W |
| Yules Spur (historical) | Locale | 1488 | Cascade | 47 02 30 N | 110 47 24 W |
| Yuletide Dam | Dam | 1010 | Blaine | 48 20 42 N | 109 06 57 W |
| Yuleville (historical) | Locale | 1488 | Cascade | 47 02 30 N | 110 47 24 W |
| Yuma Gulch | Valley | | Missoula | 46 46 50 N | 113 49 00 W |
| Yunck Dam | Dam | 1127 | Glacier | 48 41 42 N | 112 21 51 W |
| Z Cake Dam | Dam | 836 | Rosebud | 46 35 24 N | 107 04 38 W |
| Z Lake | Lake | 2996 | Carbon | 45 03 51 N | 109 44 48 W |
| Z-G Number 18 Mine | Mine | 1764 | Lewis and Clark | 46 46 04 N | 112 20 13 W |
| Zade Mountain | Summit | 2464 | Gallatin | 46 01 34 N | 111 03 01 W |
| Zanzi Pal Dam | Dam | 955 | Hill | 48 41 24 N | 110 41 45 W |