| Oregon Federal Census Index 1870 | ||||
| Baker County | Series M593 | Roll 1285 | ||
| Name | Page | Line No. | Dwelling | Family |
| O, Wy | 12B | 4 | 52 | 43 |
| O, Yet | 21A | 14 | 70 | 68 |
| O'Brien, Thomas | 31B | 22 | 69 | 61 |
| Odell, James | 32A | 25 | 83 | 75 |
| Oggle, William | 36B | 22 | 83 | 82 |
| Olds, Albert J. | 33A | 39 | 25 | 25 |
| Olds, Annie E. | 33A | 38 | 25 | 25 |
| Olds, Daniel | 33A | 36 | 25 | 25 |
| Olds, Margaret | 33B | 2 | 25 | 25 |
| Olds, Mary A. | 33A | 40 | 25 | 25 |
| Olds, Sarah L. | 33A | 37 | 25 | 25 |
| Olds, Sheridan | 33B | 1 | 25 | 25 |
| Oleson, Casper | 37A | 10 | 88 | 87 |
| Olin, John S. | 32B | 20 | 10 | 10 |
| On, Ah | 30B | 23 | 7 | 5 |
| On, Ah | 37A | 39 | 94 | 93 |
| Oneill, Charles | 27A | 26 | 79 | 72 |
| Oneill, Eveline | 27A | 23 | 79 | 72 |
| Oneill, Hugh | 27A | 21 | 79 | 72 |
| Oneill, John | 27A | 25 | 79 | 72 |
| Oneill, Margaret | 27A | 22 | 79 | 72 |
| Oneill, Minnie | 27A | 24 | 79 | 72 |
| Oo, Ah | 12A | 1 | 35 | 28 |
| Oong, Ah | 20B | 36 | 66 | 64 |
| Osborn, Drucilla | 39A | 28 | 129 | 125 |
| Osborn, Hiram | 39A | 27 | 129 | 125 |
| Osborn, Olive O. | 39A | 30 | 129 | 125 |
| Osborn, Stephen | 39A | 29 | 129 | 125 |
| Ottenheimer, Samuel | 26B | 31 | 68 | 63 |
| Ottis, P. D. | 33B | 37 | 33 | 33 |
| Ouy | 29A | 23 | 23 | 15 |
| Owens, William | 15A | 8 | 97 | 87 |
| Own, Ah | 13A | 36 | 71 | 62 |