| Public Service Company Of Indiana | Princeton | IN |
| Public Service Company Of Indiana | Kokomo | IN |
| Public Service Company Of Indiana | Cayuga | IN |
| Public Service Company Of Indiana | New Albany | IN |
| Public Service Company Of Indiana | Fayette | IN |
| Public Service Company Of Indiana | Plainfield | IN |
| Public Service Company Of Indiana | West Terre Haute | IN |
| Public Service Company Of Indiana | Edwardsport | IN |
| Public Service Company Of Indiana | Indianapolis | IN |
| Pugh | North Judson | IN |
| Pullman | Michigan City | IN |
| Pullman | Hammond | IN |
| Purdue Calumet Center Technology Building | Hammond | IN |
| Purdue Power Plant | Lafayette | IN |
| Purdue University | Indianapolis | IN |
| Purdue University | Elkhart | IN |
| Purdue University | West Lafayette | IN |
| Purdue University | Lafayette | IN |
| Pyromation | Fort Wayne | IN |
| Quaker Maid | Terre Haute | IN |
| Quality Gauge & Tool | Muncie | IN |
| Radio Corporation Of America (RCA) | Monticello | IN |
| Radio Corporation Of America (RCA) | Marion | IN |
| Radio Corporation Of America (RCA) | Indianapolis | IN |
| Ramada Inn | South Bend | IN |
| Randall Inn Motel | Roseland | IN |
| R.C.A. Whirlpool | South Bend | IN |
| Rea Magnet Wire | Fort Wayne | IN |
| Rea Magnet Wire | Lafayette | IN |
| Refinery Engineering | Mount Vernon | IN |
| Refractory Construction | South Bend | IN |
| Refractory Metals & Machine Shop | Kokomo | IN |
| Reid Memorial Hospital | Richmond | IN |
| Reilly Tar & Chemical | Indianapolis | IN |
| Reitz High School | Evansville | IN |
| Reliable Service | Fort Wayne | IN |
| Reliance Electric | Columbus | IN |
| Reliance Electric | Madison | IN |
| Rendering Plant | Evansville | IN |
| Republic Aviation | Evansville | IN |
| Republic Creosoting | Indianapolis | IN |
| Republic Steel | East Chicago | IN |
| Republic Steel | Muncie | IN |
| Republic Steel | Gary | IN |
| Rex Cleaners | Evansville | IN |
| Rex Manufacturing | Connersville | IN |
| Richard J. Bagan | Columbia | IN |
| Richardson | Indianapolis | IN |
| Richardson Rubber | Indianapolis | IN |
| Richmond Light Heat & Power | Richmond | IN |
