Counties in Iowa

• Adair (7 historic properties)
• Adams (4 historic properties)
• Allamakee (19 historic properties)
• Appanoose (13 historic properties)
• Audubon (13 historic properties)
• Benton (12 historic properties)
• Black Hawk (39 historic properties)
• Boone (18 historic properties)
• Bremer (6 historic properties)
• Buchanan (19 historic properties)
• Buena Vista (7 historic properties)
• Butler (6 historic properties)
• Calhoun (12 historic properties)
• Carroll (12 historic properties)
• Cass (10 historic properties)
• Cedar (18 historic properties)
• Cerro Gordo (40 historic properties)
• Cherokee (9 historic properties)
• Chickasaw (4 historic properties)
• Clarke (7 historic properties)
• Clay (8 historic properties)
• Clayton (52 historic properties)
• Clinton (26 historic properties)
• Crawford (14 historic properties)
• Dallas (15 historic properties)
• Davis (11 historic properties)
• Decatur (7 historic properties)
• Delaware (15 historic properties)
• Des Moines (27 historic properties)
• Dickinson (12 historic properties)
• Dubuque (73 historic properties)
• Emmet (3 historic properties)
• Fayette (28 historic properties)
• Floyd (18 historic properties)
• Franklin (11 historic properties)
• Fremont (9 historic properties)
• Greene (16 historic properties)
• Grundy (2 historic properties)
• Guthrie (6 historic properties)
• Hamilton (8 historic properties)
• Hancock (9 historic properties)
• Hardin (31 historic properties)
• Harrison (9 historic properties)
• Henry (45 historic properties)
• Howard (8 historic properties)
• Humboldt (7 historic properties)
• Ida (5 historic properties)
• Iowa (11 historic properties)
• Jackson (75 historic properties)
• Jasper (12 historic properties)

• Jefferson (28 historic properties)
• Johnson (81 historic properties)
• Jones (23 historic properties)
• Keokuk (10 historic properties)
• Kossuth (4 historic properties)
• Lee (42 historic properties)
• Linn (76 historic properties)
• Louisa (8 historic properties)
• Lucas (15 historic properties)
• Lyon (10 historic properties)
• Madison (47 historic properties)
• Mahaska (46 historic properties)
• Marion (24 historic properties)
• Marshall (14 historic properties)
• Mills (3 historic properties)
• Mitchell (10 historic properties)
• Monona (9 historic properties)
• Monroe (11 historic properties)
• Montgomery (15 historic properties)
• Muscatine (26 historic properties)
• O Brien (3 historic properties)
• Osceola (1 historic property)
• Page (8 historic properties)
• Palo Alto (4 historic properties)
• Plymouth (10 historic properties)
• Pocahontas (3 historic properties)
• Polk (167 historic properties)
• Pottawattamie (34 historic properties)
• Poweshiek (22 historic properties)
• Ringgold (6 historic properties)
• Sac (8 historic properties)
• Scott (284 historic properties)
• Shelby (11 historic properties)
• Sioux (4 historic properties)
• Story (32 historic properties)
• Tama (11 historic properties)
• Taylor (7 historic properties)
• Union (5 historic properties)
• Van Buren (21 historic properties)
• Wapello (27 historic properties)
• Warren (12 historic properties)
• Washington (14 historic properties)
• Wayne (3 historic properties)
• Webster (12 historic properties)
• Winnebago (4 historic properties)
• Winneshiek (30 historic properties)
• Woodbury (53 historic properties)
• Worth (6 historic properties)
• Wright (9 historic properties)