Clayton is a city in Clayton County, Iowa, United States. The population was 45 at the 2020 census, down from 55 in 2000. Clayton is located directly on the Mississippi River and is only accessible via a very steep road. History Clayton was founded in 1849. Geography Clayton is located at (42.902929, -91.148165). According to the United States Census Bureau, the city has a total area of , all land. Demographics 2010 census As of the census of 2010, there were 43 people, 28 households, and 14 families living in the city. The population density was . There were 84 housing units at an average density of . The racial makeup of the city was 100.0% White. There were 28 households, of which 3.6% had children under the age of 18 living with them, 42.9% were married couples living together, 7.1% had a male householder with no wife present, and 50.0% were non-families. 50.0% of all households were made up of individuals, and 14.2% had someone living alone who was 65 years of age or older. The average household size was 1.54 and the average family size was 2.07. The median age in the city was 59.3 years. 2.3% of residents were under the age of 18; 0% were between the ages of 18 and 24; 13.9% were from 25 to 44; 51.2% were from 45 to 64; and 32.6% were 65 years of age or older. The gender makeup of the city was 46.5% male and 53.5% female. 2000 census As of the census of 2000, there were 55 people, 32 households, and 19 families living in the city. The population density was . There were 64 housing units at an average density of . The racial makeup of the city was 100.00% White. There were 32 households, out of which 9.4% had children under the age of 18 living with them, 53.1% were married couples living together, 3.1% had a female householder with no husband present, and 40.6% were non-families. 40.6% of all households were made up of individuals, and 21.9% had someone living alone who was 65 years of age or older. The average household size was 1.72 and the average family size was 2.11. In the city, the population was spread out, with 5.5% under the age of 18, 1.8% from 18 to 24, 7.3% from 25 to 44, 56.4% from 45 to 64, and 29.1%