| Population Change 1990-2000 | ||||
| County or Municipality | 2000 Population | 1990 Population | Population Change | Percent Change |
| Pennsylvania | 12 281 054 | 11 881 643 | 399 411 | 3.4 |
| Elk County | 35 112 | 34 878 | 234 | 0.7 |
| Benezette township | 227 | 243 | - 16 | - 6.6 |
| Fox township | 3 734 | 3 392 | 342 | 10.1 |
| Highland township | 509 | 551 | - 42 | - 7.6 |
| Horton township | 1 574 | 1 655 | - 81 | - 4.9 |
| Jay township | 2 094 | 2 087 | 7 | 0.3 |
| Johnsonburg borough | 3 003 | 3 350 | - 347 | - 10.4 |
| Jones township | 1 721 | 1 870 | - 149 | - 8.0 |
| Millstone township | 95 | 85 | 10 | 11.8 |
| Ridgway borough | 4 591 | 4 793 | - 202 | - 4.2 |
| Ridgway township | 2 802 | 2 617 | 185 | 7.1 |
| St. Marys city | 14 502 | 14 020 | 482 | 3.4 |
| Spring Creek township | 260 | 215 | 45 | 20.9 |
| Source: U.S. Census Bureau | Prepared by: Pennsylvania State Data Center | |||