Montana - Area of significance: Architecture
| Garnet Historic District |
| Gavin House |
| Gay, Edward, House |
| Gebo Barn |
| Gebo, Henry, House |
| Gehring Ranch |
| Geraldine Milwaukee Depot |
| Gibson, A. J., House |
| Gibson, John, House |
| Gibson-Lebert House |
| Gifford House |
| Gildersleeve Mine |
| Gill, Sherman, House |
| Gilman State Bank |
| Gilpatrick-Root House |
| Gird Point Lookout |
| Glacier County Courthouse |
| Glacier Park Women's Club |
| Gleason Building |
| Gleim Building |
| Glidden House |
| Glidden Mercantile |
| Glover Cabin |
| Goff House |
| Goosetown Historic District |
| Gordon House |
| Grace Lutheran Church of Barber |
| Graf, Arnold, House |
| Graf Building |
| Graham House |
| Grandchamp House |
| Grand Pacific Hotel |
| Grand Union Hotel |
| Granite Apartments |
| Granite County Jail |
| Granite Park Chalet |
| Granke, Charles, House |
| Grant-Kohrs Ranch/Warren Ranch |
| Graves Hotel |
| Great Falls Central Business Historic District |
| Great Falls Central High School |
| Great Falls High School Historic District |
| Great Falls Northside Residential Historic District |
| Great Falls Railroad Historic District |
| Great Falls West Bank Historic District |
| Great Northern Railway Buildings |
| Great Northern Railway Passenger and Freight Depot and Division Office |
| Greenblatt, Samuel, House |
| Green Ranch |
| Gregg-Moses House |
| Greve's Tourist Cabins |
| Griffen House |
| Gunsight Pass Shelter |
| Hale's Filling Station and Grocery |
| Halfway House |
| Hall Bungalow |
| Hamill Apartments |
| Hamill House |
| Hamilton Commercial Historic District |
| Hamilton Southside Residential Historic District |
| Hamilton Town Hall |
| Hammond Arcade |
| Harmon, William, House |
| Harrington, Rose, House |
| Harris House |
| Harrison Lake Patrol Cabin |
| Harrison, Waborn (Wabe) and Sarah E., Ranch House |
| Harvat Ranch |
| Hauser Mansion |
| Haverfield Hospital |
| Havre Residential Historic District |
| Hawthorne Grade School |
| Hayward Lodge |
| Headquarters Building and Daily Company Annex |
| Headquarters Historic District |
| Hearst Free Library |
| Heaven's Peak Fire Lookout |
| Hecla House |
| Heikkila-Mattila Homestead |
| Helena Historic District |
| Helena Railroad Depot Historic District |
| Helena South-Central Historic District |
| Helena West Main Street Historic District |
| Heller Building |
| Hellgate Lodge 383 BPOE |
| Heltne Oil Company |
| Henneberry, William F., Homestead |
| Hepburn, John, Place |
| Heritage Museum, The |
| Herzog, J. M., House |
| Hi Bug Historic District |
| Higgins Block |
| Hilger, Joe and Carrie, Ranch |
| Hillcrest Cemetery |
| Hines House |
| Hodgson House |
| Hoffman, Charles, House |
| Holy Rosary Church Rectory |
| Holy Rosary Hospital |
| Hornet Lookout |
Data from United States Park Service and Wikidata
