If population growth rate would be same as in period 2010-2014 (+0.44%/yr), Arrow Rock town population in 2020 would be 59*. Arrow Rock median household income is $50,313 in 2010-2014 and has grown by … Only 1 county is shown. The typical household in Arrow Rock earns $65,125 a year, about $4,800 more than the national median of $60,293 and $11,600 more than the median household income across the state of $53,560. Arrow Rock is a town in Saline County, Missouri, with a population of 45. //-->, .