[3] The first settlement in what is today St. John was made in 1875 when William Bickerton of the Church of Jesus Christ founded a religious colony named Zion Valley.

[5] In 2015, due to diligent work of local citizens and former local graduates, the official government listing of locations has been corrected to spell the town correctly as "St. John" instead of "Saint John" that was incorrectly changed by the United States Postal Service in the 1970s.

[6] According to the United States Census Bureau, the city has a total area of 1.88 square miles (4.87 km2), all of it land.

[7] The 2020 United States census counted 1,228 people, 491 households, and 309 families in St.

There were 570 housing units at an average density of 293.2 per square mile (113.2/km2).

32.8% of households consisted of individuals and 16.7% had someone living alone who was 65 years of age or older.

[13] The percent of those with a bachelor’s degree or higher was estimated to be 17.1% of the population.

There were 642 housing units at an average density of 341.5 per square mile (131.9/km2).

34.8% of all households were made up of individuals, and 18.2% had someone living alone who was 65 years of age or older.

There were 686 housing units at an average density of 381.1 per square mile (147.1/km2).

38.1% of all households were made up of individuals, and 18.3% had someone living alone who was 65 years of age or older.