| Region 7 | ||||||||||||
| Population Age by County, 2000 | ||||||||||||
| Source: U.S. Census Bureau, Census 2000 | ||||||||||||
| Age in Years | 0-9 | 10-14 | 15-19 | 20-24 | 25-34 | 35-44 | 45-54 | 55-59 | 60-64 | 65-74 | 75-84 | 85+ |
| Bonneville | 13926 | 7670 | 7410 | 5395 | 10101 | 12325 | 10749 | 3733 | 2815 | 4485 | 2973 | 940 |
| Butte | 441 | 246 | 230 | 108 | 285 | 410 | 410 | 171 | 165 | 260 | 124 | 49 |
| Clark | 198 | 92 | 97 | 55 | 127 | 154 | 104 | 57 | 44 | 55 | 30 | 9 |
| Custer | 520 | 369 | 300 | 127 | 422 | 703 | 734 | 309 | 228 | 361 | 203 | 66 |
| Fremont | 2003 | 1051 | 1264 | 698 | 1304 | 1616 | 1356 | 581 | 477 | 844 | 460 | 165 |
| Jefferson | 3604 | 2058 | 1948 | 1182 | 2116 | 2770 | 2257 | 780 | 665 | 972 | 632 | 171 |
| Lemhi | 940 | 641 | 579 | 263 | 628 | 1147 | 1302 | 554 | 444 | 678 | 508 | 122 |
| Madison | 3780 | 2024 | 6719 | 5621 | 2101 | 2288 | 1944 | 726 | 605 | 845 | 605 | 209 |
| Teton | 1023 | 556 | 477 | 335 | 970 | 1055 | 798 | 201 | 136 | 249 | 167 | 32 |