Rock Island is a city located in Washington. With a 2020 population of 1,172, it is the 196th largest city in Washington and the 9683rd largest city in the United States. Rock Island is currently growing at a rate of 5.40% annually and its population has increased by 48.73% since the most recent census, which recorded a population of 788 in 2010. Spanning over 1 miles, Rock Island has a population density of 1,429 people per square mile.
The average household income in Rock Island is $49,630 with a poverty rate of 11.89%. The median rental costs in recent years comes to $709 per month, and the median house value is $149,600. The median age in Rock Island is 31.1 years, 31.2 years for males, and 30.9 years for females. For every 100 females there are 101.5 males.