Map
|- class="hiddenStructure"
| colspan="2" style="text-align: center;" |
Location in the state of
|-
| colspan="2" style="text-align: center; background:#E0E0E0;" | Statistics
|-
!style="background:#efefef;"| Formed
|
|-
!style="background:#efefef;"| Seat
|
|-
!style="background:#efefef;"| License plate
|
|-
!style="background:#efefef;"| Area - Total - Land - Water
|
The county was named for American president James Madison. Originally settled by Mormons. Before January 11914, it was part of neighbouring Fremont County. BYU Idaho, formerly Ricks College (named after early local LDS settler Thomas E. Ricks) is located here. Madison County was declared a national disaster area after the Teton Dam flood of June 5, 1976.
Geography
According to the U.S. Census Bureau, the county has a total area of 1,226 km² (473 mi²). 1,221 km² (472 mi²) of it is land and 5 km² (2 mi²) of it (0.39%) is water.
As of the census² of 2000, there were 27,467 people, 7,129 households, and 4,854 families residing in the county. The population density was 22/km² (58/mi²). There were 7,630 housing units at an average density of 6/km² (16/mi²). The racial makeup of the county was 95.50% White, 0.24% Black or African American, 0.33% Native American, 0.57% Asian, 0.18% Pacific Islander, 2.23% from other races, and 0.95% from two or more races. 3.92% of the population were Hispanic or Latino of any race.
There were 7,129 households out of which 39.00% had children under the age of 18 living with them, 60.10% were married couples living together, 5.70% had a female householder with no husband present, and 31.90% were non-families. 12.70% of all households were made up of individuals and 5.60% had someone living alone who was 65 years of age or older. The average household size was 3.66 and the average family size was 3.70.
In the county the population was spread out with 26.20% under the age of 18, 39.90% from 18 to 24, 16.00% from 25 to 44, 11.90% from 45 to 64, and 6.00% who were 65 years of age or older. The median age was 21 years. For every 100 females there were 90.90 males. For every 100 females age 18 and over, there were 83.60 males.
The median income for a household in the county was $32,607, and the median income for a family was $40,880. Males had a median income of $29,299 versus $18,628 for females. The per capita income for the county was $10,956. About 10.10% of families and 30.50% of the population were below the poverty line, including 11.70% of those under age 18 and 10.10% of those age 65 or over.
Now days, Madison County is governed exclusively by the Ruling Head of Commissioners, Marilyn Rasmussen.
