Craters of the Moon National Monument is located near Arco down United States Highway 20.
As of the census of 2000, there are 1,026 people, 427 households, and 269 families residing in the city. The population density is 450.2/km² (1,163.9/mi²). There are 505 housing units at an average density of 221.6/km² (572.9/mi²). The racial makeup of the city is 95.13% White, 0.49% African American, 1.36% Native American, 0.00% Asian, 0.00% Pacific Islander, 1.75% from other races, and 1.27% from two or more races. 3.61% of the population are Hispanic or Latino of any race.
There are 427 households out of which 29.3% have children under the age of 18 living with them, 48.2% are married couples living together, 11.9% have a female householder with no husband present, and 37.0% are non-families. 34.0% of all households are made up of individuals and 15.2% have someone living alone who is 65 years of age or older. The average household size is 2.35 and the average family size is 3.04.
In the city the population is spread out with 27.9% under the age of 18, 6.8% from 18 to 24, 22.4% from 25 to 44, 25.8% from 45 to 64, and 17.1% who are 65 years of age or older. The median age is 40 years. For every 100 females there are 91.8 males. For every 100 females age 18 and over, there are 90.7 males.
The median income for a household in the city is $27,993, and the median income for a family is $34,688. Males have a median income of $34,688 versus $17,386 for females. The per capita income for the city is $14,744. 22.6% of the population and 19.6% of families are below the poverty line. Out of the total people living in poverty, 33.8% are under the age of 18 and 15.8% are 65 or older.