Idaho - Area of significance: Architecture
| Abbs, Walter, House |
| Adams, Abram A., House |
| Adams County Courthouse |
| Ada Odd Fellows Temple |
| Ada Theater |
| Administration Building, University of Idaho |
| A. F. R. Building |
| Aiken's Hotel |
| Aitken Barn |
| Ake, F. P., Building |
| Albaugh, Eleanor, Cabin |
| Albion Methodist Church |
| Albion Normal School Campus |
| Alexander House |
| Alexanders |
| Allred, Ezra, Bungalow |
| Allred, Ezra, Cottage |
| Allsup, Marion, House |
| Allton Building |
| Alvis, James, House |
| American Falls East Shore Power Plants |
| American Legion Cabin |
| American Legion Hall |
| American Legion Malad Post 65 |
| American Women's League Chapter House |
| Amustutz Apartments |
| Anasola, Jose and Gertrude, House |
| Anderson-Elwell House |
| Anduiza Hotel |
| Arambarri, Galo, Boarding House |
| Arco Baptist Community Church |
| Arrowrock Dam |
| Art Troutner Houses Historic District |
| Ashley, Dr. George, House |
| Ashley, George, Sr., House |
| Asposas, James, House |
| Assay Office |
| Athay, Sam, House |
| Atlanta Historic District |
| Atlanta Ranger Station Historic District |
| Avery Ranger Station |
| Bagley, John A., House |
| Baker, James V. and Sophia, House |
| Bald Mountain Hot Springs |
| Bank of Juliaetta |
| Baptist Church |
| Barnes, Tom, Barn |
| Bate, S. A., Barn and Chicken House |
| Baugh, W. H., House |
| Bayhorse |
| Bayview School II |
| Bear Lake County Courthouse |
| Bear Lake Market |
| Bear Lake Stake Tabernacle |
| Beck, Albert, House |
| Beck Barns and Automobile Storage |
| Beckman, Andrew and Johanna M., Farm |
| Beckman, Oscar and Christina, Farmstead |
| Bellevue Historic District |
| Bellgrove School II |
| Bell, R.H. and Jessie, House |
| Bemis, Polly, House |
| Benewah County Courthouse |
| Bernard's Ferry |
| Bernd, W. A., Building |
| Berriochoa, Ignacio, Farm |
| Bethany Memorial Chapel |
| Bethune-Ayres House |
| Bickel School |
| Big Cedar School |
| Big Creek Commissary |
| Big Falls Inn |
| Bishop Mountain Lookout |
| Bishop West Barn |
| Blackfoot I.O.O.F. Hall |
| Blackfoot LDS Tabernacle |
| Blackfoot Railway Depot |
| Blaine County Courthouse |
| Blatchley Hall |
| Blessing, Carl, Outbuildings |
| Bliss, F. T., House |
| Board-and-Batten Commercial Building |
| Boarding House |
| Bohman, Axel, House |
| Bohman, Ole, House |
| Boise Capitol Area District |
| Boise City National Bank |
| Boise High School Campus |
| Boise Historic District |
| Boise Junior College Administration Building |
| Boise Junior High School |
| Bonneville County Courthouse |
| Bonneville Hotel |
| Bothwell, James, Water Tank House |
| Boulevard Mo-tel |
| Boundary County Courthouse |
| Boussuet, Birdie, Farm |
| Bower, Charles, House |
| Bowlby, T. P., Barn |
| Bown, Joseph, House |
Data from United States Park Service and Wikidata