Rigby is a city in and the county seat of Jefferson County, Idaho, United States. The population was 3,945 at the 2010 census, up from 2,998 in 2000. History Rigby was founded by members of the Church of Jesus Christ of Latter-day Saints in 1884 and incorporated in 1903. The community was named after William F. Rigby, a prominent early settler and member of the church. A significant majority of Rigby's residents, as well as those of the outlying communities, are members of the Church of Jesus Christ of Latter-Day Saints. Baptist, Presbyterian, and Lutheran faiths also have current local congregations. Geography Rigby is at an elevation of above sea level. According to the United States Census Bureau, the city has a total area of , of which, is land and is water. Many tributaries of the Snake River run through the Rigby area including the Henry’s Fork, South Fork, and others. With the large amount of water, Jefferson County surrounding Rigby is the largest cottonwood forest west of the Mississippi River. Demographics 2010 census As of the census of 2010, there were 3,945 people, 1,328 households, and 994 families living in the city. The population density was . There were 1,428 housing units at an average density of . The racial makeup of the city was 89.5% White, 0.2% African American, 0.9% Native American, 0.5% Asian, 0.2% Pacific Islander, 6.7% from other races, and 2.1% from two or more races. Hispanic or Latino of any race were 11.8% of the population. There were 1,328 households, of which 45.3% had children under the age of 18 living with them, 57.0% were married couples living together, 13.3% had a female householder with no husband present, 4.5% had a male householder with no wife present, and 25.2% were non-families. 21.8% of all households were made up of individuals, and 9% had someone living alone who was 65 years of age or older. The average household size was 2.91 and the average family size was 3.43. The median age in the city was 27.6 years. 34.3% of residents were under the age of 18; 10.3% were between the ages of 18 and 24; 28.5% were from 25 to 44; 16.5% were from 45 to 64; and 10.3% were 65 years of age or older. The gender makeup of the city was 47.4% male and 52.6% female. 2000 census As of the census of