Madison county is in southeast Idaho, a part of the Upper Snake River Valley. It is the fastest growing county in the fastest growing part of the state. Rexburg, the county seat, doubled in size between its 80th and 100th birthdays. Other communities are Archer, Burton, Byrne, Edmonds, Herbert, Hibbard, Hinckley, Jensen, Jolley, Lyman, Mark, Moody, Parkinson, Plano, Salem, Sugar City, Sunnydell, Thorton, and Walker. Main industries include farming, the Idaho National Engineering Laboratory under the direction of the U.S. Department of Energy, and Ricks College. It is 473 square miles.
It was established February 18,1913, from Fremont county. It was named for President James Madison, the fourth president of the United States. The first settlers in the county were "Mormon" families from Utah, led by Thomas E. Ricks.
| Feature Name | Latitude | Longitude | USGS 7.5' Map |
|---|---|---|---|
| Archer | 434249N | 1114655W | Ririe |
| Burton | 434751N | 1115126W | Rexburg |
| Byrne | 434131N | 1114445W | Heise |
| Edmonds | 435447N | 1115248W | Plano |
| Gale | 434555N | 1114307W | Moody |
| Hart | 435303N | 1114418W | Saint Anthony |
| Herbert | 434223N | 1113933W | Heise |
| Hibbard | 435119N | 1115016W | Rexburg |
| Hinckley | 435154N | 1115127W | Rexburg |
| Independence (historical) | 434635N | 1115458W | Menan Buttes |
| Jensen | 434434N | 1114447W | Heise |
| Jolley | 435032N | 1114638W | Rexburg |
| Lyman | 434421N | 1114901W | Ririe |
| Mark | 434631N | 1114952W | Rexburg |
| Moody | 435013N | 1113803W | Moody |
| Parkinson | 434858N | 1113930W | Moody |
| Plano | 435328N | 1115327W | Plano |
| Rexburg | 434934N | 1114720W | Rexburg |
| Salem | 435236N | 1114620W | Parker |
| Sugar City | 435223N | 1114451W | Moody |
| Sunnydell | 434104N | 1114515W | Ririe |
| Thornton | 434530N | 1115040W | Rexburg |
| Walker | 434620N | 1114228W | Moody |
| Woods Crossing | 434627N | 1113747W | Moody |