Highest salary at Grundy County in year 2020 was $73,708. Number of employees at Grundy County in year 2020 was 65. Average annual salary was $26,470 and median salary was $26,400. Grundy County average salary is 44 percent lower than USA average and median salary is 39 percent lower than USA median salary. From 2019 to 2020, the average salary of employees at this employer increased 11.0 percent, the median salary increased 19.8 percent.