The 1920 United States Census counted 1,412 residents in Arthur County, which was then and has remained entirely rural, essentially ranching. Although the village of Arthur underwent electrification in the 1920s, most of the county did not see power or telephone services until 1950–1951. At that time also, highway construction and improvements facilitated transportation, which was especially dependent upon the north-south State Highway 61 and the east-west Highway 92: motor vehicles were the sole means of mechanical transportation throughout Arthur's history as it had no railroad or canal. Irrigation of the sandhills land started by 1900 and continued through the first half of the twentieth century, with center-pivot irrigation dominating. The population peaked around 1930 at 1,344 persons, but declined with the Great Depression. By 1950, the county population was down to 803, by 1980 down to 513.